Anemias

Anemias

Definition

Anemia is a blood disorder characterized by abnormally low levels of healthy red blood cells (RBCs) or reduced hemoglobin (Hgb), the iron-bearing protein in red blood cells that delivers oxygen to tissues throughout the body. Reduced blood cell volume (hematocrit) is also considered anemia. The reduction of any or all of the three blood parameters reduces the oxygen-carrying capability of the blood, causing reduced oxygenation of body tissues, a condition called hypoxia.

Description

All tissues in the human body need a regular supply of oxygen to stay healthy and perform their functions. RBCs contain Hgb, a protein pigment that allows the cells to carry oxygen (oxygenate) tissues throughout the body. RBCs live about 120 days and are normally replaced in an orderly way by the bone marrow, spleen, and liver. As RBCs break down, they release Hgb into the blood stream, which is normally filtered out by the kidneys and excreted. The iron released from the RBCs is returned to the bone marrow to help create new cells. Anemia develops when either blood loss, a slow-down in the production of new RBCs (erythropoiesis), or an increase in red cell destruction (hemolysis) causes significant reductions in RBCs, Hgb, iron levels, and the essential delivery of oxygen to body tissues.

Anemia can be mild, moderate, or severe enough to lead to life-threatening complications. More than 400 different types of anemia have been identified. Many of them are rare. Most are caused by ongoing or sudden blood loss. Other causes include vitamin and mineral deficiencies, inherited conditions, and certain diseases that affect red cell production or destruction.

Anemia in newborn infants is noted when hemoglobin levels are lower than expected for the birth weight and postnatal age. Premature or low birth-weight infants may have lower hemoglobin levels. The normal newborn Hgb is 16.8 dL, which may be 1 to 2 dL lower if birth weight is abnormally low. Anemia may be the first sign of certain disorders in the newborn, such as blood loss that has occurred from transplacental hemorrhage, a condition in which the infant's blood bleeds back into the mother's circulation; bleeding from ruptures in the liver, spleen, adrenals, or kidneys; or hemorrhage within the brain (intracranial hemorrhage). Anemia can also be caused by the destruction of red blood cells or reduced red blood cell production. Newborns may also have low red blood cell volume (hematocrit or Hct) if they were born by cesarean section . It must be noted, however, that hemoglobin decreases naturally (physiologic decrease) in infants by eight to 12 weeks of age, leveling at a normal value of 11 g/dL or better.

Iron-deficiency anemia

Iron deficiency anemia is the most common form of anemia worldwide. In the United States, it affects thousands of toddlers between one and two years of age and more than 3 million women of childbearing age. This condition is less common in older children and in adults over 50 and rarely occurs in teenage boys and young men.

The onset of iron deficiency anemia is gradual and may not have early symptoms. The deficiency begins when the body loses more iron than it derives from food and other sources. Because depleted iron stores cannot meet the red blood cell's needs, fewer red blood cells develop. In this early stage of anemia, the red blood cells look normal, but they are reduced in number. Then the body tries to compensate for the iron deficiency by producing more red blood cells, which are characteristically small in size (spherocytosis). Symptoms of anemia, especially weakness and fatigue, develop at this stage. Individuals may be given iron preparations by injection or advised to take oral iron supplements. It sometimes helps to take vitamin C along with oral iron supplementation to encourage better absorption of the iron. Taking iron supplements can result in diarrhea , cramps, or vomiting .

Folic acid deficiency anemia

Folic acid deficiency anemia is the most common type of megaloblastic anemia, arising from a problem with the synthesis of deoxyribonucleic acid (DNA) within the cells of the body. It is characterized by RBCs that are larger than normal and is caused by a deficiency of folic acid, a vitamin that the body needs to produce normal cells and normal DNA.

Folic acid anemia is especially common in infants and teenagers. This condition usually results from a dietary deficiency but may also be due to an inability to absorb (malabsorption) folic acid. Folic acid is available in many foods, such as cheese, eggs, fish, green vegetables, meat, milk, mushrooms, and yeast. Smoking raises the risk of developing this condition by interfering with the absorption of vitamin C, which the body needs to absorb folic acid. Folic acid anemia can be a complication of pregnancy, when a woman's body needs eight times more folic acid than it does otherwise. Folic acid deficiency in pregnant women may lead to birth defects in their children. Supplementation of folic acid is recommended during pregnancy.

Vitamin B12 deficiency anemia

Less common in the United States than folic acid anemia, vitamin B12 deficiency anemia is another type of megaloblastic anemia that develops when the body does not absorb enough of this nutrient. Necessary for the creation of healthy RBCs, B12 is found in meat, eggs, whole grains, and most vegetables. Large amounts of B12 are stored in the body, so this condition may not become apparent until up to four years after B12 absorption stops or slows down. The resulting drop in RBC production can cause loss of muscle control; loss of sensation in the legs, hands, and feet; soreness, slickness, or burning of the tongue; weight loss; or yellow-blue color blindness . Confusion, depression, and memory loss may also be associated with the deficiency.

Pernicious anemia is the most common form of B12 deficiency. Since most people who eat meat or eggs get enough B12 in their diets, a deficiency of this vitamin usually means that the body is not absorbing it properly. This condition can be found in those who do not produce adequate amounts of a chemical secreted by the stomach lining that combines with B12 to help its absorption in the small intestine. Pernicious anemia is diagnosed more often in adults between ages 50 and 60 than in children or young people, although there is the possibility of inheriting the condition, with symptoms not appearing until later in life.

Vitamin C deficiency anemia

Anemia due to vitamin C deficiency is a rare disorder that causes the bone marrow to manufacture abnormally small red blood cells. Vitamin C deficiency anemia results from a severe, long-standing dietary deficiency or malabsorption of this essential vitamin. It is usually easily corrected with supplementation.

Hemolytic anemia

Hemolytic anemia can be present at birth (congenital hemolytic anemia or spherocytosis) or acquired later in life. It is the result of either infection or the presence of antibodies that destroy RBCs more rapidly than bone marrow can replace them. Hemolytic anemia can enlarge the spleen, an organ that also produces red blood cells when necessary. Production of cells by the spleen will increase to meet the demands of accelerated RBC destruction (hemolysis). Complications of hemolytic anemia in older children or adults include pain , gallstones, and other serious health problems.

Hemolytic disease of the newborn is a specific variation of hemolytic anemia in which an incompatibility exists between antigens on the cells of the mother and baby, causing antibodies to develop in the mother's circulation. The antibodies are produced as an immune response to what the body views as foreign antigens on the surface of the infant's RBCs. Several specific antigens are responsible for the incompatibilities: Rh type incompatibility, ABO blood group incompatibility, and other incompatibilities involving antigens known as Kell, Duffy, M, N, and P, among many others. Hemolytic disease of the newborn and the anemia that results is detectable within the first few days after birth. Depending on the strength of the antibody, the anemia may clear up on its own or exchange transfusions may be necessary to replace the newborn's blood.

Thalassemia

An inherited form of hemolytic anemia, thalassemia comes from the production of abnormal hemoglobin. It is characterized by low hemoglobin and unusually small and fragile RBCs (microcytosis), although the RBC count may be normal. Thalassemia has several types that involve imbalances in the four chains of amino acids that comprise hemoglobin (alpha- and beta-globins). In thalassemia minor or thalassemia trait (heterozygous thalassemia), also called alpha-thalassemia, there is an imbalance in the production of the alpha chain of amino acids. In thalassemia minor, fetal hemoglobin (HbF), the hemoglobin form that circulates in the fetus, does not decrease normally after birth and may remain high in later life. A child may inherit thalassemia trait when only one parent has the genes responsible for it. It is usually not treated and does not have serious consequences. Thalassemia major (homozygous thalassemia or Cooley's anemia) occurs in children in whom both parents pass on the genes responsible. It is known as beta-thalassemia, because of an imbalance in the beta chain amino acids of hemoglobin. It also involves the persistence of HbF with larger than normal amounts appearing in the child's circulation. Alpha-thalassemias occur most commonly in African Americans; beta-thalassemias most commonly affect people of Mediterranean or middle-Eastern ancestry and Southeast Asians. Hemoglobin H disease is another form of thalassemia in which three of the four beta-globin genes are missing.

Sickle cell anemia

Sickle cell anemia is an inherited, chronic, incurable blood disorder that causes the body to produce defective hemoglobin, the abnormal HgbS, which occurs primarily in African Americans. The condition is characterized by abnormal, crescent-shaped RBCs. Unlike normal oval cells, fragile sickle cells cannot hold enough hemoglobin to nourish body tissues. The deformed shape makes it hard for sickle cells to pass through narrow blood vessels. When capillaries become obstructed, a life-threatening condition called sickle cell crisis is likely to occur. A child who inherits the sickle cell gene from each parent will have the disease. A child who inherits the sickle cell gene from only one parent carries the sickle cell trait but does not have the disease.

Aplastic anemia

Sometimes curable by bone marrow transplant, but potentially fatal, aplastic anemia is characterized by decreased production of red and white blood cells and platelets (disc-shaped cells that are a key component of blood coagulation). This disorder may be inherited or acquired as a result of the following:

  • recent severe illness
  • long-term exposure to industrial chemicals
  • chemotherapy, use of anticancer drugs, and certain other medications

Anemia of chronic disease

Cancer , chronic infection or inflammation, and kidney and liver disease often cause mild or moderate anemia. Chronic liver failure generally produces the most severe symptoms because the production of RBCs is directly affected.

Causes and symptoms

Anemias do not all stem from the same causes. Anemia can be the result of injuries, chronic or acute illnesses, complications of surgery or childbirth , metabolic disturbances or deficiencies, and adverse response to drug therapy administered for other conditions. Causes may include sudden or ongoing loss of blood, nutritional deficiencies, decreased red blood cell production, or increased red blood cell destruction. Malnutrition or malabsorption of nutrients can contribute to vitamin deficiency anemia and iron deficiency anemias. Although red cell destruction and replacement is an ongoing process in the body, hereditary disorders and certain diseases can accelerate blood cell destruction, resulting in anemia. However, excessive bleeding is the most common cause of severe anemia, and the speed with which blood loss occurs has a significant effect on the severity of symptoms. Chronic blood loss may be a consequence of the following:

  • cancer
  • gastrointestinal tumors
  • diverticulosis
  • polyposis
  • heavy or frequent menstrual flow
  • hemorrhoids
  • nosebleeds
  • stomach ulcers
  • long-standing alcohol abuse

Acute blood loss may occur as a result of injury, a ruptured blood vessel, or a complication of surgery or childbirth. When a lot of blood is lost within a short time, blood pressure and the amount of oxygen in the body drop suddenly, sometimes leading to heart failure or death. Loss of even one third of the body's blood volume in the space of several hours can be fatal. Gradual blood loss is less threatening, because the body has time to replace RBCs and blood volume.

Symptoms

Weakness, fatigue, and a run-down feeling may be the first signs of anemia. Pasty or sallow skin color, or the absence of color in the gums, nail beds, creases of the palm, or lining of the eyelids are other signs of anemia. Individuals who appear to be weak, easily tired, often out of breath, and who may feel faint or dizzy on movement may be severely anemic.

Other symptoms of anemia may include the following:

  • unusual cravings for ice (chewing on ice cubes), paint, or earth (actually eating dirt)
  • headache
  • inability to concentrate, memory loss
  • inflammation of the mouth (stomatitis ) or tongue (glossitis)
  • insomnia
  • irregular heartbeat
  • loss of appetite
  • dry, brittle, or ridged nails
  • rapid breathing
  • sores in the mouth, throat, or rectum
  • perspiration, especially around the head and neck
  • swelling of hands and feet
  • constant thirst
  • ringing in the ears (tinnitus)
  • unexplained bleeding or bruising
  • angina pectoris, i.e., chest pain accompanied by a choking sensation that may provoke anxiety

Demographics

Acquired anemias affect about 4 million individuals in the United States, and over 50 percent of these are under age 45, although less than 10 percent of cases occur in children and adolescents. In the United States, iron deficiency anemia is the most prevalent type of anemia, affecting about 240,000 toddlers between one and two years of age and 3.3 million women of childbearing age. Anemia due to gradual blood loss is more common in women than in men, particularly pregnant women or women of menstruating age. Pernicious anemia is more common in women and in African Americans and is less common in other racial groups. Folate deficiency is not common in young people who eat an adequate diet and is usually associated with malnutrition, pregnancy, and alcoholism . Sickle cell anemia is more frequently diagnosed than thalassemias and occurs most often among African Americans. Thalassemia occurs in four out of 100,000 individuals in the United States, particularly among those of Mediterranean, Asian, or middle Eastern descent.

When to call the doctor

When a child exhibits weakness, dizziness , listlessness, or fatigue, it may be the first sign of anemia. The pediatrician should be consulted if the child is also extremely pale or has little or no color in the gums, nail beds, creases of the palm, or lining of the eyelids. Any prolonged bleeding or sudden blood loss requires examination by a physician and testing for anemia.

Diagnosis

The child's medical history will be taken, including the child's age, symptoms, illnesses, and general state of health, and a family history of ancestry and known inherited anemias will be noted. Symptoms noticed in children by their parents may include fatigue, weight loss, inability to concentrate, loss of appetite, and light-headedness when standing up. The physical examination may reveal paleness, lack of color in the creases of the palm, gums, and the linings of the eyelids. The child's breathing rate may be increased and, in advanced cases, the spleen or liver may be enlarged when palpated. If anemia is due to chronic disease, there may be evidence of infection or inflammation. Urine output may be reduced in severe anemia.

Diagnostic testing begins with a complete blood count (CBC) and differential to reveal the RBC count, white blood cell (WBC) count, hemoglobin (Hgb), and hematocrit (Hct); any of these counts can be altered, and in most anemias the RBC and hemoglobin will be reduced. The mean corpuscular volume (MCV) will be measured to compare the size of RBCs with normal RBCs. A reticulocyte (young RBCs) count will help determine if anemia is caused by impaired RBC production or increased RBC destruction. Iron, vitamin C, vitamin B12, and folate levels will be measured to evaluate and identify possible deficiencies. Diagnosing thalassemia and sickle cell anemia, both of which involve disorders of hemoglobin, will require measuring the different types of hemoglobin through a laboratory testing method called hemoglobin electrophoresis. In some anemias, a bone marrow sample will be removed (bone marrow biopsy) for microscopic examination, especially to confirm iron deficiency anemia or the megaloblastic anemias. Kidney function tests, coagulation tests, and stool examinations for occult blood may also be performed.

Treatment

Surgery may be necessary to correct blood losses caused by injury or hemorrhage (nose bleeds, aneurysm, cerebral hemorrhage, bleeding ulcer) or childbirth. Transfusions of packed red blood cells or whole blood may also be used to replace blood volume and to stimulate the body's own production of red blood cells. Medication or surgery may also be necessary to control heavy menstrual flow or to remove polyps (growths or nodules) from the bowels.

Anemia due to nutritional deficiencies can usually be treated with iron replacement therapy, specific vitamin supplements, or self-administered injections of vitamin B12. People with folic acid anemia may be advised to take oral folic acid.

Vitamin B12 deficiency anemia requires a life-long regimen of B12 shots to maintain vitamin levels and control symptoms of pernicious anemia. The patient may be advised to limit physical activity until treatment restores strength and balance.

Anemia resulting from chronic disease is typically corrected by treating the underlying illness. This type of anemia rarely becomes severe. If it does, transfusions or hormone treatments to stimulate red blood cell production may be given.

Thalassemia minor is typically not treated. Thalassemia major may be treated with regular transfusions, surgical resection of the spleen to avoid its removal of RBCs from circulation, and sometimes iron chelation therapy. Symptoms are treated as they occur. Children or young adults with thalassemia major may require periodic hospitalization to receive blood transfusions or, in some cases, bone marrow transplants.

Sickle cell anemia will be monitored by regular eye examinations and diagnostic blood work. Immunizations for pneumonia and infectious diseases are part of treatment along with prompt treatment for sickle cell crises and infections of any kind. Psychotherapy or counseling may help older children deal with the emotional symptoms characteristic of this condition.

Children with aplastic anemia are especially susceptible to infection. Treatment for aplastic anemia may involve blood transfusions and bone marrow transplantation to replace malfunctioning cells with healthy ones.

Hemolytic anemia of the warm-antibody type may be treated with large doses of intravenous and oral corticocosteroids (cortisone). Individuals who do not respond to medical therapy, may undergo surgery to remove the spleen, which controls the anemia in some individuals by helping to add more RBCs to the circulation. Immune-system suppressants are prescribed when surgery is not successful. There is no specific treatment for cold-anti-body hemolytic anemia.

Treatment of newborn anemia depends on the severity of symptoms, the level of Hgb, and the presence of any other diseases that may affect oxygen delivery, such as lung or heart disease or hyaline membrane disease. Transfusions may be given in certain situations or exchange transfusions if hemolytic disease of the newborn is not quickly resolved. The risk of transfusion (such as transfusion reactions, potential toxins, and infections such as HIV or hepatitis) are carefully weighed against the severity of the anemia in the infant.

Alternative treatment

Vitamin C is noted for helping to absorb iron and folate supplements. Cooking in a cast iron skillet may leach small amounts of absorbable iron into the diet. Folic acid can be readily absorbed from raw salad greens such as lettuce, spinach, arugula, alfalfa sprouts, and others. Blackstrap molasses is a good source of iron and B vitamins . Herbal supplements that will benefit individuals who have anemia include bilberry, dandelion, goldenseal, mullein, nettle, Oregon grape root, red raspberry, and yellow dock. Herbs are available as tinctures and teas or in capsules.

Nutritional concerns

The diet is a ready source of nutrients that prevent and treat anemia. Children with anemia can include more of these nutrients in their diet by eating a broad variety of whole grains, fruits and vegetables, beans, lean meat, poultry and fish, and supplementing the diet regularly with vitamins, minerals , and iron (as recommended). Pediatricians should be consulted before iron supplements are taken, however, because of the difficulty in absorbing non-food sources of iron. Vitamin C can stimulate iron absorption. Good food sources of iron include: almonds, broccoli, dried beans, raisins, dried apricots, seaweed (as soup stock), whole-grain breads and cereals, brown rice, lean red meat, liver, potatoes, poultry, and shellfish.

Because light and heat destroy folic acid, fruits and vegetables should be eaten raw or cooked as little as possible to help assimilation of folic acid. Folic acid can also be taken as a supplement.

Prognosis

Most anemias can be treated or managed. The prognosis for anemias generally depends upon the severity of the anemia, the type of anemia, and the response to treatment. The hereditary anemias, such as the thalassemias and sickle cell anemia, may require life-long treatment and monitoring whereas other types of anemia, once treated, are apt not to recur. Thalassemia major may cause deformities and may shorten life expectancy. Severe anemia may lead to other serious conditions, particularly if oxygen delivery is compromised for long periods of time or RBC destruction is more rapid than can be controlled by normal RBC replacement or specific treatment. Severe blood loss or prolonged anemia can result in life-threatening complications.

Prevention

Safety is the primary preventive measure for blood loss by injury. A wholesome, balanced diet rich in nutrients can help prevent dietary deficiencies that lead to anemia. Hereditary anemias cannot be prevented; parents can seek genetic testing and counseling if they are concerned about inherited anemias noted in their families or ethnic background.

Nutritional concerns

Sources of iron such as liver, red meat, whole grains, and poultry may help maintain hemoglobin levels and reduce the likelihood of deficiency-related anemias. Vitamin C is noted for helping to improve assimilation of iron taken as supplements.

Parental concerns

Parents may be particularly concerned about the possibility of inherited anemias. Genetic testing is available to address their doubts. Nutrition education is readily available from public health sources, books, and the reliable Internet sources for parents who are concerned about providing essential nutrients for children who may be susceptible to deficiency anemias. Regular physical examinations can help evaluate a child's overall health and reveal possible signs or symptoms of anemia.

KEY TERMS

Erythropoiesis The process through which new red blood cells are created; it begins in the bone marrow.

Hematocrit A measure of the percentage of red blood cells in the total volume of blood in the human body.

Hemoglobin An iron-containing pigment of red blood cells composed of four amino acid chains (alpha, beta, gamma, delta) that delivers oxygen from the lungs to the cells of the body and carries carbon dioxide from the cells to the lungs.

Hemolysis The process of breaking down of red blood cells. As the cells are destroyed, hemoglobin, the component of red blood cells which carries the oxygen, is liberated.

Hypoxia A condition characterized by insufficient oxygen in the cells of the body

Megaloblast A large erythroblast (a red marrow cell that synthesizes hemoglobin).

Reticulocyte An early, immature form of a red blood cell. Over time, the reticulocyte develops to become a mature, oxygen-carrying red blood cell.

Resources

BOOKS

"Blood Disorders." The Merck Manual of Medical Information, 2nd Home ed. Edited by Mark H. Beers et al. White House Station, NJ: Merck & Co., 2003.

Hill, Shirley, A. Managing Sickle Cell Disease in Low-Income Families. Philadelphia: Temple University Press, 2003.

Lande, Bruce. Aplastic Anemia and Other Autoimmune Diseases: Help Your Body Heal Itself. Syracuse, NY: Action Enterprises, 2003.

Ross, Allison J. Everything You Need to Know about Anemia. New York: Rosen Publishing Group, 2001.

Wick, M., et al. Iron Metabolism, Anemias, Clinical Aspects and Laboratory. New York: Springer, 2003.

ORGANIZATIONS

National Heart, Lung, and Blood Institute (NHLBI). 6701 Rockledge Drive, PO Box 30105, Bethesda, MD 208240105. Web site: <http://www.nhlbi.nih.gov>.

WEB SITES

"Anemia." KidsHealth. Available online at <http://kidshealth.org/parent/medical/heart/anemia.html> (accessed October 10, 2004).

"Understanding Anemia: Your Life May Depend on It." Anemia Lifeline. Available online at <www.anemia.com> (accessed October 10, 2004).

L. Lee Culvert Maureen Haggerty

Anemias

Anemias

Definition

Anemia is a condition characterized by abnormally low levels of healthy red blood cells or hemoglobin (the component of red blood cells that delivers oxygen to tissues throughout the body).

Description

The tissues of the human body need a regular supply of oxygen to stay healthy. Red blood cells, which contain hemoglobin that allows them to deliver oxygen throughout the body, live for only about 120 days. When they die, the iron they contain is returned to the bone marrow and used to create new red blood cells. Anemia develops when heavy bleeding causes significant iron loss or when something happens to slow down the production of red blood cells or to increase the rate at which they are destroyed.

Types of anemia

Anemia can be mild, moderate, or severe enough to lead to life-threatening complications. More than 400 different types of anemia have been identified. Many of them are rare.

IRON DEFICIENCY ANEMIA. The onset of iron deficiency anemia is gradual and, at first, there may not be any symptoms. The deficiency begins when the body loses more iron than it derives from food and other sources. Because depleted iron stores cannot meet the red blood cell's needs, fewer red blood cells develop. In this early stage of anemia, the red blood cells look normal, but they are reduced in number. Then the body tries to compensate for the iron deficiency by producing more red blood cells, which are characteristically small in size. Symptoms develop at this stage.

FOLIC ACID DEFICIENCY ANEMIA. Folic acid anemia is especially common in infants and teenagers. Although this condition usually results from a dietary deficiency, it is sometimes due to inability to absorb enough folic acid from such foods as:

  • cheese
  • eggs
  • fish
  • green vegetables
  • meat
  • milk
  • mushrooms
  • yeast

Smoking raises the risk of developing this condition by interfering with the absorption of Vitamin C, which the body needs to absorb folic acid. Folic acid anemia can be a complication of pregnancy, when a woman's body needs eight times more folic acid than it does otherwise.

VITAMIN B12 DEFICIENCY ANEMIA. Less common in this country than folic acid anemia, vitamin B12 deficiency anemia is another type of megaloblastic anemia that develops when the body doesn't absorb enough of this nutrient. Necessary for the creation of red blood cells, B12 is found in meat and vegetables.

Large amounts of B12 are stored in the body, so this condition may not become apparent until as much as four years after B12 absorption stops or slows down. The resulting drop in red blood cell production can cause:

  • loss of muscle control
  • loss of sensation in the legs, hands, and feet
  • soreness or burning of the tongue
  • weight loss
  • yellow-blue color blindness

The most common form of B12 deficiency is pernicious anemia. Since most people who eat meat or eggs get enough B12 in their diets, a deficiency of this vitamin usually means that the body is not absorbing it properly. This can occur among people who have had intestinal surgery or among those who do not produce adequate amounts of intrinsic factor, a chemical secreted by the stomach lining that combines with B12 to help its absorption in the small intestine.

Pernicious anemia usually strikes between the ages of 50-60. Eating disorders or an unbalanced diet increase the risk of developing pernicious anemia. So do:

  • diabetes mellitus
  • gastritis, stomach cancer, or stomach surgery
  • thyroid disease
  • family history of pernicious anemia

VITAMIN C DEFICIENCY ANEMIA. A rare disorder that causes the bone marrow to manufacture abnormally small red blood cells, Vitamin C deficiency anemia results from a severe, long-standing dietary deficiency.

HEMOLYTIC ANEMIA. Some people are born with hemolytic anemia. Some acquire this condition, in which infection or antibodies destroy red blood cells more rapidly than bone marrow can replace them.

Hemolytic anemia can enlarge the spleen, accelerating the destruction of red blood cells (hemolysis). Other complications of hemolytic anemia include:

  • pain
  • shock
  • gallstones and other serious health problems

KEY TERMS

Aplastic Exhibiting incomplete or faulty development.

Hemoglobin An iron-containing pigment of red blood cells composed of four amino acid chains (alpha, beta, gamma, delta) that delivers oxygen from the lungs to the tissues of the body.

Megaloblast A large erythroblast (a red marrow cell that synthesizes hemoglobin).

THALASSEMIAS. An inherited form of hemolytic anemia, thalassemia stems from the body's inability to manufacture as much normal hemoglobin as it needs. There are two categories of thalassemia, depending on which of the amino acid chains is affected. (Hemoglobin is composed of four chains of amino acids.) In alpha-thalassemia, there is an imbalance in the production of the alpha chain of amino acids; in beta-thalassemia, there is an imbalance in the beta chain. Alpha-thalassemias most commonly affect blacks (25% have at least one gene); beta-thalassemias most commonly affect people of Mediterranean ancestry and Southeast Asians.

Characterized by production of red blood cells that are unusually small and fragile, thalassemia only affects people who inherit the gene for it from each parent (autosomal recessive inheritance).

AUTOIMMUNE HEMOLYTIC ANEMIAS. Warm antibody hemolytic anemia is the most common type of this disorder. This condition occurs when the body produces autoantibodies that coat red blood cells. The coated cells are destroyed by the spleen, liver, or bone marrow.

Warm antibody hemolytic anemia is more common in women than in men. About one-third of patients who have warm antibody hemolytic anemia also have lymphoma, leukemia, lupus, or connective tissue disease.

In cold antibody hemolytic anemia, the body attacks red blood cells at or below normal body temperature. The acute form of this condition frequently develops in people who have had pneumonia, mononeucleosis, or other acute infections. It tends to be mild and short-lived, and disappears without treatment.

Chronic cold antibody hemolytic anemia is most common in women and most often affects those who are over 40 and who have arthritis. This condition usually lasts for a lifetime, generally causing few symptoms. However, exposure to cold temperatures can accelerate red blood cell destruction, causing fatigue, joint aches, and discoloration of the arms and hands.

SICKLE CELL ANEMIA. Sickle cell anemia is a chronic, incurable condition that causes the body to produce defective hemoglobin, which forces red blood cells to assume an abnormal crescent shape. Unlike normal oval cells, fragile sickle cells can't hold enough hemoglobin to nourish body tissues. The deformed shape makes it hard for sickle cells to pass through narrow blood vessels. When capillaries become obstructed, a life-threatening condition called sickle cell crisis is likely to occur.

Sickle cell anemia is hereditary. It almost always affects blacks and people of Mediterranean descent. A child who inherits the sickle cell gene from each parent will have the disease. A child who inherits the sickle cell gene from only one parent carries the sickle cell trait, but does not have the disease.

APLASTIC ANEMIA. Sometimes curable by bone marrow transplant, but potentially fatal, aplastic anemia is characterized by decreased production of red and white blood cells and platelets (disc-shaped cells that allow the blood to clot). This disorder may be inherited or acquired as a result of:

  • recent severe illness
  • long-term exposure to industrial chemicals
  • use of anticancer drugs and certain other medications

ANEMIA OF CHRONIC DISEASE. Cancer, chronic infection or inflammation, and kidney and liver disease often cause mild or moderate anemia. Chronic liver failure generally produces the most severe symptoms. People infected with the Human immunodeficiency virus (HIV) that causes AIDS often face severe fatigue.

Causes and symptoms

Anemia is caused by bleeding, decreased red blood cell production, or increased red blood cell destruction. Poor diet can contribute to vitamin deficiency and iron deficiency anemias in which fewer red blood cells are produced. Hereditary disorders and certain diseases can cause increased blood cell destruction. However, excessive bleeding is the most common cause of anemia, and the speed with which blood loss occurs has a significant effect on the severity of symptoms. Chronic blood loss is usually a consequence of:

  • cancer
  • gastrointestinal tumors
  • diverticulosis
  • polyposis
  • heavy menstrual flow
  • hemorrhoids
  • nosebleeds
  • stomach ulcers
  • long-standing alcohol abuse

Acute blood loss is usually the result of:

  • childbirth
  • injury
  • a ruptured blood vessel
  • surgery

When a lot of blood is lost within a short time, blood pressure and the amount of oxygen in the body drop suddenly. Heart failure and death can follow.

Loss of even one-third of the body's blood volume in the space of several hours can be fatal. More gradual blood loss is less serious, because the body has time to create new red blood cells to replace those that have been lost.

Symptoms

Weakness, fatigue, and a run-down feeling may be signs of mild anemia. Skin that is pasty or sallow, or lack of color in the creases of the palm, gums, nail beds, or lining of the eyelids are other signs of anemia. Someone who is weak, tires easily, is often out of breath, and feels faint or dizzy may be severely anemic.

Other symptoms of anemia are:

  • angina pectoris (chest pain, often accompanied by a choking sensation that provokes severe anxiety )
  • cravings for ice, paint, or dirt
  • headache
  • inability to concentrate, memory loss
  • inflammation of the mouth (stomatitis ) or tongue (glossitis)
  • insomnia
  • irregular heartbeat
  • loss of appetite
  • nails that are dry, brittle, or ridged
  • rapid breathing
  • sores in the mouth, throat, or rectum
  • sweating
  • swelling of the hands and feet
  • thirst
  • tinnitus (ringing in the ears)
  • unexplained bleeding or bruising

In pernicious anemia, the tongue feels unusually slick. A patient with pernicious anemia may have:

  • problems with movement or balance
  • tingling in the hands and feet
  • confusion, depression, and memory loss

Pernicious anemia can damage the spinal cord. A doctor should be notified whenever symptoms of this condition occur.

A doctor should also be notified if a patient who has been taking iron supplements develops:

  • diarrhea
  • cramps
  • vomiting

Diagnosis

Personal and family health history may suggest the presence of certain types of anemia. Laboratory tests that measure the percentage of red blood cells or the amount of hemoglobin in the blood are used to confirm diagnosis and determine which type of anemia is responsible for a patient's symptoms. X rays and examinations of bone marrow may be used to identify the source of bleeding.

Treatment

Anemia due to nutritional deficiencies can usually be treated at home with iron supplements or self administered injections of vitamin B12. People with folic acid anemia should take oral folic acid replacements. Vitamin C deficiency anemia can be cured by taking one vitamin C tablet a day.

Surgery may be necessary to treat anemia caused by excessive loss of blood. Transfusions of red blood cells may be used to accelerate production of red blood cells.

Medication or surgery may also be necessary to control heavy menstrual flow, repair a bleeding ulcer, or remove polyps (growths or nodules) from the bowels.

Patients with thalassemia usually do not require treatment. However people with a severe form may require periodic hospitalization for blood transfusions and/or bone marrow transplantation.

SICKLE CELL ANEMIA. Treatment for sickle cell anemia involves regular eye examinations, immunizations for pneumonia and infectious diseases, and prompt treatment for sickle cell crises and infections of any kind. Psychotherapy or counseling may help patients deal with the emotional impact of this condition.

VITAMIN B12 DEFICIENCY ANEMIA. A life-long regimen of B12 shots is necessary to control symptoms of pernicious anemia. The patient may be advised to limit physical activity until treatment restores strength and balance.

APLASTIC ANEMIA. People who have aplastic anemia are especially susceptible to infection. Treatment for aplastic anemia may involve blood transfusions and bone marrow transplant to replace malfunctioning cells with healthy ones.

ANEMIA OF CHRONIC DISEASE. There is no specific treatment for anemia associated with chronic disease, but treating the underlying illness may alleviate this condition. Erythropoietin is a hormone that stimulates production of red blood cells. It is sometimes used to treat anemia from kidney disease or cancer chemotherapy. This type of anemia rarely becomes severe. If it does, transfusions or hormone treatments to stimulate red blood cell production may be prescribed. A working group met in 2004 to address the specific management of anemia in patients infected with HIV.

HEMOLYTIC ANEMIA. There is no specific treatment for cold-antibody hemolytic anemia. About one-third of patients with warm-antibody hemolytic anemia respond well to large doses of intravenous and oral corticosteroids, which are gradually discontinued as the patient's condition improves. Patients with this condition who don't respond to medical therapy must have the spleen surgically removed. This operation controls anemia in about one-half of the patients on whom it's performed. Immune-system suppressants are prescribed for patients whose surgery is not successful.

Self-care

Anyone who has anemia caused by poor nutrition should modify his or her diet to include more vitamins, minerals, and iron. Vitamin C can stimulate iron absorption. The following foods are also good sources of iron:

  • almonds
  • broccoli
  • dried beans
  • dried fruits
  • enriched breads and cereals
  • lean red meat
  • liver
  • potatoes
  • poultry
  • rice
  • shellfish
  • tomatoes

Because light and heat destroy folic acid, fruits and vegetables should be eaten raw or cooked as little as possible.

Alternative treatment

As is the case in standard medical treatment, the cause of the specific anemia will determine the alternative treatment recommended. If the cause is a deficiency, for example iron deficiency, folic acid deficiency, B12 deficiency, or vitamin C deficiency, supplementation is the treatment. For extensive blood loss, the cause should be identified and corrected. Other types of anemias should be addressed on a deep healing level with crisis intervention when necessary.

Many alternative therapies for iron-deficiency anemia focus on adding iron-rich foods to the diet or on techniques to improve circulation and digestion. Iron supplementation, especially with iron citrate (less likely to cause constipation ), is used by alternative practitioners. This can be given in combination with herbs that are rich in iron. Some examples of iron-rich herbs are dandelion (Taraxacum officinale ), parsley (Petroselinum crispum ), and nettle (Urtica dioica ). The homeopathic remedy ferrum phosphoricum can also be helpful.

An iron-rich herbal tonic can also me made using the following recipe:

  • soak 1/2 oz of yellow dock root and 1/2 oz dandelion root in 1 qt of boiled water for four to 8 hours
  • strain and simmer until the amount of liquid is reduced to 1 cup
  • remove from heat and add 1/2 cup black strap molasses, mixing well
  • store in refrigerator; take 1 tsp-2 Tbsp daily

Other herbal remedies used to treat iron-deficiency anemia aim to improve the digestion. Gentian (Gentiana lutea ) is widely used in Europe to treat anemia and other nutritionally based disorders. The bitter qualities of gentian help stimulate the digestive system, making iron and other nutrients more available for absorption. This bitter herb can be brewed into tea or purchased as an alcoholic extract (tincture).

Other herbs recommended to promote digestion include:

  • anise (Pimpinella anisum )
  • caraway (Carum carvi )
  • cumin (Cuminum cyminum )
  • linden (Tilia spp.)
  • licorice (Glycyrrhiza glabra )

Traditional Chinese treatments for anemia include:

  • acupuncture to stimulate a weakened spleen
  • asian ginseng (Panax ginseng ) to restore energy
  • dong quai (Angelica sinensis ) to control heavy menstrual bleeding
  • a mixture of dong quai and Chinese foxglove (Rehmannia glutinosa ) to clear a sallow complexion

Prognosis

Folic-acid and iron-deficiency anemias

It usually takes three to six weeks to correct folic acid or iron deficiency anemia. Patients should continue taking supplements for another six months to replenish iron reserves. They should have periodic blood tests to make sure the bleeding has stopped and the anemia has not recurred.

Pernicious anemia

Although pernicious anemia is considered incurable, regular B12 shots will alleviate symptoms and reverse complications. Some symptoms will disappear almost as soon as treatment begins.

Aplastic anemia

Aplastic anemia can sometimes be cured by bone marrow transplantation. If the condition is due to immunosuppressive drugs, symptoms may disappear after the drugs are discontinued.

Sickle cell anemia

Although sickle cell anemia cannot be cured, effective treatments enable patients with this disease to enjoy longer, more productive lives.

Thalassemia

People with mild thalassemia (alpha thalassemia trait or beta thalassemia minor) lead normal lives and do not require treatment. Those with severe thalassemia may require bone marrow transplantation. Genetic therapy is is being investigated and may soon be available.

Hemolytic anemia

Acquired hemolytic anemia can generally be cured when the cause is removed.

Prevention

Inherited anemias cannot be prevented. Genetic counseling can help parents cope with questions and concerns about transmitting disease-causing genes to their children.

Avoiding excessive use of alcohol, eating a balanced diet that contains plenty of iron-rich foods, and taking a daily multivitamin can help prevent anemia.

Methods of preventing specific types of anemia include:

  • avoiding lengthy exposure to industrial chemicals and drugs known to cause aplastic anemia
  • not taking medication that has triggered hemolytic anemia and not eating foods that have caused hemolysis (breakdown of red blood cells)
  • receiving regular B12 shots to prevent pernicious anemia resulting from gastritis or stomach surgery

Resources

PERIODICALS

"Biopharmaceuitcal Company Announces Manufacturing Agreement for Anemia Drug." Obesity, Wellness, & Fitness Week (September 4, 2004): 406.

"Management Strategy for Anemia in HIV Infection Elucidated." Immunotherapy Weekly (July 7, 2004): 75.

Anemia

Anemia

Definition

Anemia is a condition characterized by abnormally low levels of healthy red blood cells or hemoglobin.

Description

The tissues of the human body need a regular supply of oxygen to stay healthy. Red blood cells, which contain hemoglobin that allows them to deliver oxygen throughout the body, live for only about 120 days. When they die, the iron they contain is returned to the bone marrow and used to create new red blood cells. Anemia can develop when heavy bleeding causes significant iron loss. It also occurs when something happens to slow down the production of red blood cells or to increase the rate at which they are destroyed.

Anemia can be mild, moderate, or severe enough to lead to life-threatening complications. Over 400 different types of anemia have been identified. Many of them are rare. More common anemia types include:

  • iron deficiency anemia
  • folic acid deficiency anemia
  • vitamin B 12 deficiency anemia
  • vitamin C deficiency anemia
  • autoimmune hemolytic anemia
  • hemolytic anemia
  • sickle cell anemia
  • aplastic anemia
  • anemia of chronic disease

Causes & symptoms

Anemia is caused by bleeding, decreased red blood cell production, or increased red blood cell destruction. Poor diet can contribute to vitamin deficiency and iron deficiency anemia, in which fewer red blood cells are produced. Hereditary disorders and certain diseases can cause increased blood cell destruction. However, excessive bleeding is the most common cause of anemia, and the speed with which blood loss occurs has a significant effect on the severity of symptoms. Chronic blood loss may be caused by:

  • heavy menstrual flow
  • hemorrhoids
  • nosebleeds
  • cancer
  • gastrointestinal tumors
  • diverticulosis
  • polyposis
  • stomach ulcers
  • long-term alcohol abuse

Acute blood loss is usually the result of:

  • childbirth
  • injury
  • ruptured blood vessel
  • surgery

Iron deficiency anemia

Iron deficiency anemia is the most common form of anemia in the world. In the United States, iron deficiency anemia affects about 240,000 toddlers between one and two years of age and 3.3 million women of childbearing age. This condition is less common in older children and in adults over 50, and it rarely occurs in teenage boys and young men.

The onset of iron deficiency anemia is gradual. The deficiency begins when the body loses more iron than it gains from food and other sources. Because depleted iron stores cannot meet the red blood cells' needs, fewer red blood cells develop. In this early stage of anemia, the red blood cells look normal, but they are reduced in number. Then the body tries to compensate for the iron deficiency by producing more red blood cells, which are characteristically small in size.

Weakness, fatigue , and a run-down feeling may be signs of mild anemia. Other signs include skin that is pasty or sallow, or lack of color in the creases of the palm, gums, nail beds, or lining of the eyelids. Someone who is weak, tires easily, is often out of breath, and feels faint or dizzy may be severely anemic. Other symptoms of anemia are:

  • angina pectoris (chest pain )
  • headache
  • inability to concentrate and/or memory loss
  • inflammation of the mouth (stomatitis) or tongue (glossitis)
  • insomnia
  • irregular heartbeat
  • loss of appetite
  • nails that are dry, brittle, or ridged
  • rapid breathing
  • sores in the mouth, throat, or rectum
  • sweating
  • swelling of the hands and feet
  • thirst
  • tinnitus (ringing in the ears)
  • unexplained bleeding or bruising
  • pica (a craving to chew ice, paint, or dirt)

Folic acid deficiency anemia

Folic acid deficiency anemia is the most common type of megaloblastic anemia, in which red blood cells are bigger than normal. It is caused by a deficiency of folic acid, a vitamin that the body needs to produce normal cells.

Folic acid anemia is especially common in infants and teenagers. Although this condition usually results from a dietary deficiency, it is sometimes due to an inability to absorb enough folic acid from foods such as:

  • eggs
  • fish
  • green vegetables
  • meat
  • milk and cheese
  • mushrooms
  • yeast

Smoking raises the risk of developing this condition by interfering with the absorption of vitamin C, which the body needs to absorb folic acid. Folic acid anemia can be a complication of pregnancy , when a woman's body needs eight times more folic acid than it does otherwise.

Vitamin B12 deficiency anemia

Less common in this country than folic acid anemia, vitamin B12 deficiency anemia is another type of megaloblastic anemia that develops when the body does not absorb enough of this nutrient. Necessary for the creation of red blood cells, B12 is found in meat and vegetables.

Large amounts of B12 are stored in the body, so this condition may not become apparent until as long as four years after B12 absorption slows down or stops. The resulting drop in red blood cell production can cause:

  • loss of muscle control
  • loss of sensation in the legs, hands, and feet
  • soreness or burning of the tongue
  • weight loss
  • yellow-blue color blindness

The most common form of B12 deficiency is pernicious anemia. Since most people who eat meat or eggs get enough B12 in their diets , a deficiency of this vitamin usually means that the body is not absorbing it properly. This can occur among people who have had intestinal surgery or those who do not produce adequate amounts of intrinsic factor, a chemical secreted by the stomach lining that combines with B12 to help its absorption in the small intestine. Symptoms of pernicious anemia include problems with movement or balance, a slick tongue, tingling in the hands and feet, confusion, depression , and memory loss. Pernicious anemia can also damage the spinal cord. A doctor should be notified whenever symptoms of this condition occur.

Pernicious anemia usually strikes people 5060 years of age. Eating disorders or an unbalanced diet increases the risk of developing pernicious anemia. So do diabetes mellitus, gastritis , stomach cancer, stomach surgery, thyroid disease, and family history of pernicious anemia.

Vitamin C deficiency anemia

A rare disorder that causes the bone marrow to manufacture abnormally small red blood cells, vitamin C deficiency anemia results from a severe, long-standing dietary deficiency.

Hemolytic anemia

Some people are born with hemolytic anemia. Some acquire this condition, in which infection or antibodies destroy red blood cells more rapidly than bone marrow can replace them.

Hemolytic anemia can enlarge the spleen and accelerate the destruction of red blood cells (hemolysis). Other complications of hemolytic anemia may include pain, shock, gallstones , and other serious health problems.

Thalassemias

An inherited form of hemolytic anemia, thalassemia stems from the body's inability to manufacture as much normal hemoglobin as it needs. There are two categories of thalassemia, depending on which of the amino acid chains is affected. (Hemoglobin is composed of four chains of amino acids.) In alpha-thalassemia, there is an imbalance in the production of the alpha chain of amino acids ; in beta-thalassemia, there is an imbalance in the beta chain. Alpha-thalassemias most commonly affect blacks (25% have at least one gene); beta-thalassemias most commonly affect people of Mediterranean and Southeast Asian ancestry.

Characterized by production of red blood cells that are unusually small and fragile, thalassemia only affects people who inherit the gene for it from each parent (autosomal recessive inheritance).

Autoimmune hemolytic anemia

Warm antibody hemolytic anemia is the most common type of this disorder. This condition occurs when the body produces autoantibodies that coat red blood cells. The coated cells are destroyed by the spleen, liver, or bone marrow.

Warm antibody hemolytic anemia is more common in women than in men. About one-third of patients who have warm antibody hemolytic anemia also have lymphoma, leukemia , lupus, or connective tissue disease.

In cold antibody hemolytic anemia, the body attacks red blood cells at or below normal body temperature. The acute form of this condition frequently develops in people who have had pneumonia, mononucleosis , or other acute infections . It tends to be mild and short-lived, and disappears without treatment.

Chronic cold antibody hemolytic anemia is most common in women and most often affects those who are over 40 and have arthritis. This condition usually lasts for a lifetime, generally causing few symptoms. However, exposure to cold temperatures can accelerate red blood cell destruction, causing fatigue, joint aches, and discoloration of the arms and hands.

Sickle cell anemia

Sickle cell anemia is a chronic, incurable condition that causes the body to produce defective hemoglobin, which forces red blood cells to assume an abnormal crescent shape. Unlike normal oval cells, fragile sickle cells cannot hold enough hemoglobin to nourish body tissues. The deformed shape makes it hard for sickle cells to pass through narrow blood vessels. When capillaries become obstructed, a life-threatening condition called sickle cell crisis is likely to occur.

Sickle cell anemia is hereditary. It almost always affects people of African or Mediterranean descent. A child who inherits the sickle cell gene from each parent will have the disease, but a child who inherits the gene from only one parent will carry the sickle cell trait, but will not have the disease.

Aplastic anemia

Sometimes curable by bone marrow transplant, but potentially fatal, aplastic anemia is characterized by decreased production of red and white blood cells and platelets (disc-shaped cells that allow the blood to clot). This disorder may be inherited or acquired as a result of recent severe illness, long-term exposure to industrial chemicals, or use of anticancer drugs and certain other medications.

Anemia of chronic disease

Cancer, chronic infection or inflammation, and kidney and liver disease often cause mild or moderate anemia. Chronic liver failure generally produces the most severe symptoms.

Diagnosis

Personal and family health history may suggest the presence of certain types of anemia. Laboratory tests that measure the percentage of red blood cells or the amount of hemoglobin in the blood are used to confirm diagnosis and determine which type of anemia is responsible for a patient's symptoms. X rays and examinations of bone marrow may be used to identify the source of bleeding.

Treatment

Anyone who has anemia caused by poor nutrition should modify his or her diet to include more vitamins, minerals, and iron. Foods such as lean red meats, dried beans and fruits, liver, poultry, and enriched breads and cereals are all good sources of iron. In addition, eating foods rich in vitamin C such as citrus fruits and juices can promote the absorption of iron.

Patients diagnosed with iron-deficiency anemia should undergo a thorough physical examination and medical history to determine the cause of the anemia, particularly if chronic or acute blood loss is suspected. The cause of a specific anemia will determine the type of treatment recommended.

Anemia due to nutritional deficiencies can usually be treated at home with iron supplements or self administered injections of vitamin B12. People with folic acid anemia should take oral folic acid replacements. Vitamin C deficiency anemia can be cured by taking daily supplements of vitamin C.

Many therapies for iron-deficiency anemia focus on adding iron-rich foods to the diet or on techniques to improve circulation and digestion. Iron supplementation, especially with iron citrate (less likely to cause constipation ), can be given in combination with herbs that are rich in iron. Some examples of iron-rich herbs are dandelion (Taraxacum officinale ), parsley (Petroselinum crispum ), and nettle (Urtica dioica ). The homeopathic remedy ferrum phosphoricum (iron sulfate) can also be helpful.

An iron-rich herbal tonic can also be made using the following recipe:

  • Soak one-half ounce of yellow dock root and one-half ounce dandelion root in 1 qt of boiled water for 48 hours.
  • Simmer until the amount of liquid is reduced to 1 cup.
  • Remove from heat and add one-half cup black strap molasses, mixing well.
  • Store in refrigerator; take one-quarter cup daily.

Other herbal remedies known to promote digestion are prescribed to treat iron-deficiency anemia. Gentian (Gentiana lutea ) is widely used in Europe to treat anemia and other nutritionally-based disorders. The bitter qualities of gentian help stimulate the digestive system, making iron and other nutrients more available for absorption. This bitter herb can be brewed into tea or purchased as an alcoholic extract (tincture).

Other herbs recommended to promote digestion include:

  • anise (Pimpinella anisum )
  • caraway (Carum carvi )
  • cumin (Cuminum cyminum )
  • linden (Tilia spp.)
  • licorice (Glycyrrhiza glabra )

Traditional Chinese treatments for anemia include:

  • acupuncture to stimulate a weakened spleen
  • asian ginseng (Panax ginseng ) to restore energy
  • dong quai (Angelica sinensis ) to control heavy menstrual bleeding
  • a mixture of dong quai and Chinese foxglove (Rehmannia glutinosa ) to clear a sallow complexion
  • astragalus (Astragalus membranaceus ) to treat pallor and dizziness

Allopathic treatment

Surgery may be necessary to treat anemia caused by excessive loss of blood. Transfusions of red blood cells may be used to accelerate production of red blood cells.

Medication or surgery may also be necessary to control heavy menstrual flow, repair a bleeding ulcer, or remove polyps (growths or nodules) from the bowels.

Patients with thalassemia usually do not require treatment. However people with a severe form may require periodic hospitalization for blood transfusions and/or bone marrow transplantation.

Sickle cell anemia

Treatment for sickle cell anemia involves regular eye examinations, immunizations for pneumonia and infectious diseases, and prompt treatment for sickle cell crises and infections of any kind. Psychotherapy or counseling may help patients deal with the emotional impact of this condition.

Vitamin B12 deficiency anemia

A life-long regimen of B12 shots is necessary to control symptoms of pernicious anemia. The patient may be advised to limit physical activity until treatment restores strength and balance.

Aplastic anemia

People who have aplastic anemia are especially susceptible to infection. Treatment for aplastic anemia may involve blood transfusions and bone marrow transplant to replace malfunctioning cells with healthy ones.

Anemia of chronic disease

There is no specific treatment for anemia associated with chronic disease, but treating the underlying illness may alleviate this condition. This type of anemia rarely becomes severe. If it does, transfusions or hormone treatments to stimulate red blood cell production may be prescribed.

Hemolytic anemia

There is no specific treatment for cold-antibody hemolytic anemia. About one-third of patients with warm-antibody hemolytic anemia respond well to large doses of intravenous and oral corticosteroids, which are gradually discontinued as the patient's condition improves. Patients with this condition who do not respond to medical therapy must have the spleen surgically removed. This operation controls anemia in about half of the patients on whom it is performed. Immune-system suppressants are prescribed for patients whose surgery is not successful.

Expected results

Folic acid and iron deficiency anemia

It usually takes three to six weeks to correct folic acid or iron deficiency anemia. Patients should continue taking supplements for another six months to replenish iron reserves and should have periodic blood tests to make sure the bleeding has stopped and the anemia has not recurred.

Pernicious anemia

Although pernicious anemia is considered incurable, regular B12 shots will alleviate symptoms and reverse complications. Some symptoms will disappear almost as soon as treatment begins.

Aplastic anemia

Aplastic anemia can sometimes be cured by a bone marrow transplant. If the condition is due to immunosuppressive drugs, symptoms may disappear after the drugs are discontinued.

Sickle cell anemia

Although sickle cell anemia cannot be cured, effective treatments enable patients with this disease to enjoy longer, more productive lives.

Thalassemia

People with mild thalassemia (alpha thalassemia trait or beta thalassemia minor) lead normal lives and do not require treatment. Those with severe thalassemia may require bone marrow transplantation. Genetic therapy is being investigated and may soon be available.

Hemolytic anemia

Acquired hemolytic anemia can generally be cured when the cause is removed.

Prevention

Inherited anemia cannot be prevented. Genetic counseling can help parents cope with questions and concerns about passing on disease-causing genes to their children.

Avoiding excessive use of alcohol, eating a balanced diet that contains plenty of iron-rich foods, and taking a daily multivitamin can help prevent anemia.

Methods of preventing specific types of anemia include:

  • Avoiding lengthy exposure to industrial chemicals and drugs known to cause aplastic anemia.
  • Not taking medication that has triggered hemolytic anemia and not eating foods that have caused hemolysis (breakdown of red blood cells).
  • Receiving regular B12 shots to prevent pernicious anemia resulting from gastritis or stomach surgery.

Resources

BOOKS

Fauci, Anthony S. et al., eds. Harrison's Principles of Internal Medicine. New York: McGraw-Hill, 1998.

Tierney, Lawrence M., Jr. Current Medical Diagnosis & Treatment, 1998. Stamford, Conn.: Appleton & Lange, 1998.

Paula Ford-Martin

Anemia

Anemia

Description

Anemia is characterized by an abnormally low number of red blood cells in the circulating blood. It frequently affects patients with cancer. In fact, in many cancer diagnoses such as multiple myeloma and acute leukemia , the presence of anemia may be what initially prompts a doctor to suspect an underlying tumor (neoplasm). Whether or not anemia develops depends on the type of cancer found, the treatment employed, as well as the presence or absence of other underlying medical disorders.

Symptoms of malignancy-associated anemia may range from weakness, pallor, and fatigue to shortness of breath and increased heart rate. Symptoms of anemia can compromise a patient's ability to tolerate treatment, and may severely interfere with activities of daily living. Anemia may be particularly problematic in older individuals with cancer. The incidence and severity of anemia tends to increase as the cancer progresses.

Blood is comprised of three major cell types: white blood cells, which help the body fight infection; platelets, which help the blood to clot when necessary; and red blood cells, which transport oxygen from the lungs to the tissues in the body, and then transport carbon dioxide from those tissues back to the lungs. This exchange is enabled by the most important component of red blood cellsthe protein called hemoglobin that binds easily to oxygen and carbon dioxide.

Red blood cells are produced in the bone marrow through a process called erythropoiesis. When the bone marrow functions normally, it continuously replaces red blood cells to maintain a normal level that allows for adequate oxygenation of the tissues. The hormone erythropoietin stimulates red blood cell production and sends a message to the bone marrow to increase production when oxygen levels in the body are low. This mechanism is often impaired in patients with cancer.

Causes

The causes of anemia are multifactorial, and often those factors act in conjunction with one another. Generally, anemia may result from a direct effect of a cancerous tumor, or from an indirect effect of the tumor. The cancer process may directly cause anemia through two main mechanisms: blood loss or bone marrow replacement. However, most cases of anemia in cancer patients result from the indirect effects of the cancer.

Direct effects of the tumor

Anemia is a frequent complication of cancers due to bleeding. Cancers of the head and neck, the gastrointestinal and genitourinary system, and the cervix are frequently associated with endogenous bleeding, or bleeding that occurs outside the body. Bleeding occasionally develops within the tumor itself, particularly in sarcomas , melanomas, and ovarian and liver carcinomas.

A second direct cause of anemia in cancer is bone marrow replacement, which inhibits the body's ability to appropriately produce red blood cells. Certain cancers, such as acute leukemia, lymphoma and myeloma , directly suppress bone marrow function, thereby causing anemia. Other types of cancer, such as prostate or breast cancer , often spread to the bone marrow, inhibiting red blood cell production by actually replacing the bone marrow itself.

Indirect effects of the tumor

Anemia of chronic disease, also called anemia of malignancy, is the most common type of anemia seen in individuals with cancer. It is a diagnosis made only after other possible causes are ruled out and if very specific conditions are met. The presence of low levels of iron coupled with normal levels of storage iron helps distinguish anemia of chronic disease from iron deficiency anemia. Factors that cause anemia of chronic disease are not entirely clear. However, it is believed that cytokines (non-antibody proteins) produced by the tumor reduce production of and impair responsiveness to erythropoietin. Typically, this type of anemia develops slowly. Rapid development of anemia may indicate another cause.

Treatments used to manage cancer have been implicated in the development of anemia in cancer patients. Radiation therapy to large areas of bone marrow, as in the hip area, may suppress bone marrow function and lead to anemia. Chemotherapy can also cause bone marrow suppression, some drugs by specifically targeting red blood cell production. Studies have shown that 10 to 40% of patients taking cisplatin develop significant anemia. Cisplatin, a chemotherapy drug with potentially toxic effects to the kidneys, is believed to reduce the production of the hormone erythropoietin in the kidneys. Although most treatment-induced bone marrow suppression is short term, there is some evidence to support the possibility of long-term problems with blood cell production.

Treatment can increase the risk of anemia in other ways. Chemotherapy, for example, causes bone marrow suppression that may reduce the immune system's ability to fight off opportunistic infection. The resulting infections can impact the bone marrow's functioning, possibly leading to the development of anemia.

Hemolytic anemia is a type of anemia in which the red blood cell has a shortened lifespan (normal lifespan is 90-120 days). Because the bone marrow is not able to compensate by producing more red blood cells, anemia results. Abnormalities in the red blood cells may be intrinsic or may be caused by environmental factors such as auto-antibodies to red blood cells or damage from chemotherapy.

Although one factor may have a greater influence, it is important to realize that several factors may be causing anemia. For example, approximately 70% of patients with multiple myeloma are anemic at the time of diagnosis. Anemia in these cases is caused by a combination of mechanisms including bone marrow replacement with cancer cells, bone marrow suppression from chemotherapy, and impaired production of erythropoietin.

Treatments

Treatment of the anemia is directed at the underlying cause. In many cases, treating or removing the cancer corrects the red blood cell deficit. Management of autoimmune hemolytic anemia, which can be associated with chronic lymphocytic leukemia , may range from the administration of corticosteroids to the surgical removal of the spleen. More commonly, cancer-related anemias are treated with blood transfusions and/or a drug called epoetin alfa.

Blood transfusions

Blood transfusions have been the principle treatment for anemia for many years. Until the 1960s, only whole blood was given. Then, methods of separating whole blood were devised, allowing only particular components, such as platelets, red blood cells, or plasma, to be transfused.

Blood transfusions are not without risk, and must be used carefully. Many patients react to the white blood cell antigens by developing a fever . This is so common that patients are routinely premedicated to prevent fever from developing. Individuals with long-term transfusion needs, such as patients with leukemia, may be given blood products with a reduced number of white blood cells to reduce the risk of sensitization to transfused blood.

Cytomegalovirus (CMV) is a virus that may be present in blood products. Although it has no effect on individuals with normally functioning immune systems, cancer patients often have a diminished ability to fight infection. These patients may be at risk for CMV if they are CMV negative and receive CMV-positive blood.

Transfusion-associated graft-versus-host disease (TA-GvHD) is another risk factor associated with blood transfusions in cancer patients. Although it is very rare, it is often fatal. With TA-GvHD, the patient's immune system does not recognize the white blood cells in the donor blood as "nonself." The donor white blood cells, however, recognize the patient as "nonself, " and an immune-mediated reaction ensues. To prevent this reaction in at-risk patients, blood may be irradiated prior to transfusion.

Epoetin alfa

As mentioned previously, erythropoietin is a protein produced in the kidneys that stimulates red blood cell production. Using DNA technology, this hormone has been replicated to create the drug epoetin alfa for the treatment of anemia in select cancer patients. (The drug is also called erythropoietin. ) The use of this drug in the cancer setting has shown great promise, both in the treatment of cancer-related anemia, and in the reduction in the need for blood transfusion.

However, epoetin alfa therapy is not advisable for everyone. This drug is not recommended for use in cancer-related anemia caused by bleeding, hemolysis, or iron deficiencies. Nor is it recommended for patients with hypertension or albumin sensitivity. Because no human studies are available to determine its effect on a fetus, women taking epoetin alfa should take measures to prevent pregnancy.

Cancer patients with anemia who are undergoing chemotherapy may benefit from this drug. Studies have shown an increased hematocrit (the volume percentage of red blood cells in whole blood) level and a decreased need for blood transfusions after the first month of therapy in this population. Epoetin alfa is injected three times a week, and throughout therapy, blood cell counts are monitored closely.

Resources

BOOKS

Abeloff, M., et al. (Eds.) "Hematopoietic Dysfunction by Hematologic Lineage." In Clinical Oncology, 2nd Ed. New York: Churchill Livingstone Publishers, 2000.

Lee, G. and C. Bennett (Eds.) "Nonmetastatic Effects of Cancer: Other Systems." In Cecil Textbook of Medicine, 21st Ed. Philadelphia, PA: W. B. Saunders Co., 2000.

Lee, G., et al. (Eds.) Wintrobe's Clinical Hematology. Baltimore, MD: Williams & Wilkins Publishing, 1999.

Varricchio, C., (Ed.) "Cytopenias." In A Cancer Source Book for Nurses Atlanta: Jones and Bartlett Publishers, 1997, pp.161-73.

PERIODICALS

Frenkel, E.P., et al. "Anemia of Malignancy." Hematology Oncology Clinics of North America (August 1996): 861-873.

Moniterno, A.R. "Anemia of Cancer." Hematology Oncology Clinics of North America (April 1996): 345-363.

Rytting, M., et al. "Hematologic Complications of Cancer." Hematology Oncology Clinics of North America (April 1996): 366-376.

Wuest, D. "Transfusion and Stem Cell Support in Cancer Treatment." Hematology Oncology Clinics of North America (April 1996): 397-429.

Tamara Brown, R.N.

KEY TERMS

Cytokines

Non-antibody proteins released by a group of cells that act as mediators in immune response.

Cytomegalovirus (CMV)

A virus sometimes present in blood products.

Erythropoiesis

The process in which red blood cells are produced in the bone marrow.

Erythropoietin

A hormone produced by the kidneys that stimulates the production of red blood cells in a process called erythropoiesis.

Hematocrit

The volume percentage of red blood cells in whole blood.

Hemoglobin

A protein in red blood cells that transports oxygen to tissues.

Anemia

Anemia

Anemia affects more than 30 percent of the world's population, and it is one of the most important worldwide health problems. It has a significant prevalence in both developing and industrialized nations. Causes of anemia include nutritional deficiencies , particularly of iron , vitamin B12, and folate (folic acid); excess blood loss from menstruation or chronic illness and infection; ingestion of toxic substances, such as lead, ethanol, and other compounds; and genetic abnormalities such as thalassemia and sideroblastosis .

Anemia is caused by a deficiency in the intake and absorption elements required to make red blood cells. The condition is defined as one in which the blood is deficient in red blood cells, in hemoglobin , or in total volume. This results in blood that is incapable of meeting the oxygen needs of the body's tissues. Anemia is characterized by changes in the size and color of red blood cells. Red blood cells, or erythrocytes, are primarily responsible for oxygen transport from the lungs to the body's many cells. Hemoglobin is an oxygen-carrying protein in the red blood cell that incorporates iron into its structure. Therefore, iron is an essential building block of blood erythrocytes. When red blood cells are larger than normal, the anemia is termed macrocytic, and when they are smaller than normal, it is called microcytic. Normal red cell color is termed normochromic, and if the red cells appear pale, the anemia is called hypochromic. When extensive lab testing is not available for diagnosis, the use of a portable colorimeter can be used to detect anemia.

Iron-Deficiency Anemia

Anemia in the developing world is most commonly caused by an iron deficiency, which affects up to 50 percent of the population in some countries. Iron deficiency not only impairs the production of red cells in the blood, but also affects general cell growth and proliferation in tissues like the nervous system and the gastrointestinal tract. Red cells in a patient with iron-deficiency anemia are both microcytic and hypochromic.

Iron deficiency affects young children, adolescents, and women of reproductive agethree periods of rapid growth during which the body's iron needs are higher than normal. In children, iron requirements are highest between the ages of six and eighteen months, and can be ten times the requirement of a normal adult. Iron is commonly absorbed from both human milk and cow's milk, and, if consumed in good quantities, these sources can meet the body's iron needs. A deficiency can result from inadequate intake, or it can occur if milk remains the sole source of a child's nutrition after the age of four months, when iron needs exceed that provided by milk alone. Research in Chile has shown that 40 percent of children whose main source of nutrition was breast milk developed iron-deficiency anemia. Such children can appear tired and inattentive, and they can suffer from delayed motor development. Some children can even develop mild to moderate mental retardation as a result of iron-deficiency anemia. Recent research has shown that iron-deficiency anemia can also contribute to emotional development problems, with malnourished children acting more irritable and fussy.

Type Lab values Causes
Macrocytic, normochromic MCV: > 100fl MCHC: 34 Vitamin B12 deficiency, folate deficiency, vitamin C deficiency, chemotherapy (megaloblastic marrow); aplastic anemia, hypothyroidism (normoblastic marrow)
Microcytic, hypochromic MCV: < 80 MCHC: < 30 Iron deficiency, thalassemia, sideroblastic anemia, chronic lead poisoning, anemia of chronic illness
Normocytic, normochromic MCV: 8099fl MCHC: 34 + / -2 Iron deficiency (early), chronic disease
MCV: mean corpuscular volume
MCHS: mean corpuscular hemoglobin concentration
fl: femtoliter (one quadrillionth of a liter)

Pregnant women can have up to double the requirement of iron for a normal adult, with the majority of the mother's iron being transferred to her growing fetus. Adult diets in most of the developing world tend to be iron-poor, and a low dietary intake can result in iron deficiency. Deficiency can also occur as a result of poor iron absorption due to gastrointestinal pathology, blood loss due to normal menstruation, blood loss from parasitic infections such as hookworm and malaria , and blood loss from chronic diarrheaall of which are common in developing countries.

Other Causes

The two other primary causes of nutritional anemia are deficiencies in vitamin B12 and folic acid, both of which are necessary for the production of DNA , RNA , and protein. Without these necessary factors, red blood cells can develop abnormally, or even die prematurely in the bone marrow where they are made. This leads to what is known as megaloblastic anemia.

Folate deficiency is most often caused by poor intestinal absorption or low intake of folate-rich foods, such as human milk, cow's milk, fruits, green vegetables, and certain meats. It is also caused by congenital defects in intestinal absorption. Just as with iron, folic acid requirements are highest during periods of rapid growth, particularly infancy and pregnancy. Folate-deficient children present with common symptoms of anemia, as well as chronic diarrhea. Folate deficiency can also occur with kwashiorkor or marasmus . If it occurs during pregnancy, folate deficiency can lead to neural tube defects, spontaneous abortions, and prematurity.

Vitamin B12, derived from a substance called cobalamin, is mainly found in meats and other animal productshumans cannot synthesize this vitamin on their own. A good amount of its absorption depends on the presence of a substance called intrinsic factor (see sidebar). It does not normally occur with kwashiorkor or marasmus. Both folate and vitamin B12 deficiencies have also been linked to cardiovascular disease, mood disorders, and increased frequency of chromosomal breaks (which may contribute to the development of cancer ).

Pernicious Anemia

Pernicious anemia is a common cause of cobalamin/vitamin B12 deficiency. It is primarily a disease of the elderly and caused by an abnormality in the immune system where the body creates antibodies to intrinsic factor (a substance that facilitates absorption of vitamin B12) or to the cells in the stomach that secrete it. The lack of intrinsic factor B12 leads to vitamin B12 deficiency. It can also be caused by physiologic or anatomic disturbances of the stomach that might prevent intrinsic factor secretion. In children, an atypical and rare form of pernicious anemia can be inherited. It is an autosomal recessive disorder that results in an inability to secrete intrinsic factor, and it presents with anorexia, weakness, a painful red tongue, and neurologic abnormalities.

Treatment

Each of the important causes of nutritional anemia can be eradicated through prevention and treatment. Many countries have begun this process by instituting food supplementation programs in which grains and cereals are fortified with iron, folate, or vitamin B12. Given adequate resources, these deficiencies can also be ameliorated with direct oral supplements of absorbable iron, vitamin B12, and folic acid. Injectable forms of iron are also available. It has been found that the supplementation of vitamin A to at-risk populations improves anemia more efficiently than iron supplementation alone.

Treatment plans must also focus on the causes of anemia and therefore must include sanitation, treatment of infections such as malaria and HIV, and, most important, treatment of intestinal parasites . Much work is needed to address general malnutrition not only concerning these deficiencies, but also other commonly occurring ones (e.g., vitamin A, zinc , copper, calcium ). Programs dedicated to decreasing the rates of infection and illness in developing countriesthrough health education, immunization, sanitation, and appropriate treatmentwill also contribute to a lower incidence and prevalence of worldwide anemia.

see also Kwashiorkor; Malnutrition; Marasmus; Nutritional Deficiency; Vitamins, Water Soluble.

Seema P. Kumar

Bibliography

Behrman, Robert E.; Kliegman, Robert M.; and Jenson, Hal B., eds. (2000). Nelson Textbook of Pediatrics, 16th edition. Philadelphia, PA: W. B. Saunders.

Hoffbrand, A. V., and Herbert, V. (1999). "Nutritional Anemias." Seminars in Hematology 36(4).

Isselbacher, Kurt J. (1994). Harrison's Textbook of Internal Medicine, 13th edition. New York: McGraw-Hill.

Pollitt, E. (2000). "Developmental Sequela from Early Nutritional Deficiencies: Conclusive and Probability Judgments." Journal of Nutrition 130.

Ramakrishnan, U., ed. (2001). Nutritional Anemias. Boca Raton, FL: CRC Press.

Rhoades, R. A., and Tanner, G. A. (1995). Medical Physiology. Boston: Little Brown.

Yip, R., and Ramakrishnan, U. (2002). "Experiences and Challenges in Developing Countries." Journal of Nutrition 132.

anaemia

anaemia The main task of red blood cells is to transport oxygen bound to haemoglobin from the lungs to the tissues. Anaemia is a condition in which the circulating red cell mass is insufficient to serve this function normally. It is usually defined by measuring the haemoglobin level in the blood. Because of the wide range of haemoglobin values at different ages and in different populations the definition of anaemia involves the adoption of arbitrary criteria. The World Health Organization recommends that anaemia should be considered to exist in adults with haemoglobin levels lower than 13 grams per decilitre (g/dl) (males) or 12 g/dl (females). Children aged 6 months to 6 years are considered to be anaemic if their haemoglobin levels are below 11 g/dl, and those 6–14 years, below 12 g/dl.

At haemoglobin values not less than 8–9 g/dl, compensatory mechanisms involving subtle changes in the chemistry of the red cell are brought into play, such that adequate oxygenation of the tissues is maintained and there may be no symptoms. However, even at this moderately reduced haemoglobin level it has been found that the ability to work and carry out day-to-day activities is impaired. Below 8 g/dl, further compensatory mechanisms are required, including an increased cardiac output: faster heart rate and greater volume of blood pumped out at each beat. At less than 5 g/dl even these mechanisms fail to maintain oxygenation of the organs and tissues; there are symptoms and signs of oxygen deprivation and, eventually, of heart failure. These include lethargy, shortness of breath, pallor, a rapid bounding pulse, accumulation of fluid in the tissues (oedema), buzzing in the ears (tinnitus), visual disturbances, and chest pain due to reduced oxygen delivery to the heart muscle.

Anaemia is an important world health problem. It is estimated that it affects 47% of all women, 59% of pregnant women, and 26% of men in the developing world. In the richer, developed countries, it affects approximately 10% of women and 3% of men at some time during their lives.

Anaemia results either from defective production of red blood cells and their contents, or from their increased rate of destruction or loss from the body. Most forms of anaemia are acquired during a person's lifetime. There are also some inherited varieties but, with the exception of the genetic disorders of haemoglobin, these are extremely rare.

Red cells are the products of precursors that proliferate in the bone marrow and develop through a series of stages to produce mature forms. The commonest cause of anaemia is defective proliferation and maturation due to iron deficiency, because iron is a necessary component of the haemoglobin molecule. In the developing countries this is normally the result of poor diet, often combined with blood loss due to parasitic infection, particularly hookworm. In richer countries iron deficiency may also be due to diet, or to chronic bleeding. Common causes include duodenal ulcers, haemorrhoids, bowel cancer, and uterine bleeding. Heavy or even normal menstrual blood loss may be a cause if there is not adequate iron in the diet. Iron deficiency anaemias are described as hypochromic and microcytic, meaning that the red blood cells are pale and small.

As well as iron, red cell production also requires certain vitamins, particularly B12 and folic acid. Their deficiency results in a failure of red cell maturation, with the production of large, immature red cells that are called macrocytes; hence anaemias of this type are called macrocytic. Vitamin B12 deficiency usually follows autoimmune (self-destructive) damage to the stomach, leading to the defective production of intrinsic factor, a protein that is required for its absorption. Occasionally it results from dietary deficiency, but only in total vegetarians (vegans), because it is present only in animal sources. Because vitamin B12 is also required for the normal function of the nervous system, the resulting disease, pernicious anaemia is characterized by neurological disturbances as well as profound anaemia. Folic acid deficiency may be nutritional or due to disease of the small bowel — coeliac disease for example — leading to its defective absorption. This also causes a macrocytic anaemia, but without the neurological features of vitamin B12 deficiency.

Anaemia may also result from defective proliferation of red cell precursors. This may follow the action of drugs or toxins that damage the bone marrow, causing aplastic anaemia or infiltration of the marrow with neoplastic (cancer) cells, usually those associated with different forms of leukaemia.

Normally, red cells survive in the circulation for about 120 days, when they are disrupted by haemolysis, and their chemical components recycled. Anaemia can occur if their survival time is shortened, such that replacement cannot keep up with destruction. These haemolytic anaemias may be due to inherited abnormalities of the red cell membrane, of the cells' internal chemical pathways, or of haemoglobin; or they may develop because of production of antibodies that destroy red cells, or by damage to the microscopic blood vessels, which has the same effect. Genetic defects of the red cell membrane may cause the red cells to assume a spherical rather than a biconcave shape, or alter their configuration to an elliptical form. Inherited abnormalities involving the chemistry of the red cell are rarer. The only common anaemia of this type is due to the deficiency of an enzyme called glucose-6-phosphate dehydrogenase. This disorder, which affects millions of people world-wide, results in a haemolytic anaemia in response to a variety of drugs.

By far the most widespread genetic forms of anaemia are those that involve the structure or synthesis of haemoglobin. The commonest structural abnormality is sickle cell anaemia, in which an inherited defect in the structure of globin makes red cells assume a sickle shape when the oxygen tension of the blood falls; sickled cells are prematurely destroyed, causing a haemolytic anaemia. The commonest genetic disorders of haemoglobin are the thalassaemias; diseases due to the defective synthesis of the α or β chains of haemoglobin. Some forms of thalassaemia cause profound anaemia due to ineffective red cell production; they affect hundreds of thousands of children throughout the Mediterranean region, the Middle East, Indian subcontinent, and South-east Asia.

Mark Weatherall, and D. J. Weatherall


See also blood.

anemia

anemia (ənē´mēə), condition in which the concentration of hemoglobin in the circulating blood is below normal. Such a condition is caused by a deficient number of erythrocytes (red blood cells), an abnormally low level of hemoglobin in the individual cells, or both these conditions simultaneously. Regardless of the cause, all types of anemia cause similar signs and symptoms because of the blood's reduced capacity to carry oxygen. These symptoms include pallor of the skin and mucous membranes, weakness, dizziness, easy fatigability, and drowsiness. Severe cases show difficulty in breathing, heart abnormalities, and digestive complaints.

One of the most common anemias, iron-deficiency anemia, is caused by insufficient iron, an element essential for the formation of hemoglobin in the erythrocytes. In most adults (except pregnant women) the cause is chronic blood loss rather than insufficient iron in the diet, and, therefore, the treatment includes locating the source of abnormal bleeding in addition to the administration of iron.

Pernicious anemia causes an increased production of erythrocytes that are structurally abnormal and have attenuated life spans. This condition rarely occurs before age 35 and is inherited, being more prevalent among persons of Scandinavian, Irish, and English extraction. It is caused by the inability of the body to absorb vitamin B12 (which is essential for the maturation of erythrocytes).

There are several conditions that cause the destruction of erythrocytes, thereby producing anemia. Allergic-type reactions to bacterial toxins and various chemical agents, among them sulfonamides and benzene, can cause hemolysis, which requires emergency treatment. In addition, there are unusual situations in which the body produces antibodies against its own erythrocytes; the mechanism triggering such reactions remains obscure.

There are several inherited anemias that are more common among dark-skinned people. Sickle cell disease is inherited as a recessive trait almost exclusively among blacks; the condition is characterized by a chemical abnormality of the hemoglobin molecule that causes the erythrocytes to be misshapen. In 1957 Vernon Ingram determined the amino acid sequence of hemoglobin, and found the beta-globins (which is one of the two polypeptide chain types) that are found in the tetrameric (four-chain) hemoglobin protein. In sickle cell disease a single mutation produces the amino acid valine instead of glutamic acid in one of the protein chain types that make up the hemoglobin molecule.

In thalassemia major (Cooley's anemia), which is the most serious of the hereditary anemias among people of Mediterranean, Middle Eastern, and S Chinese ancestry, the erythrocytes are abnormally shaped. Symptoms include enlarged liver and spleen and jaundice. Thalassemia major usually causes death before adulthood is reached.

Any disease or injury to the bone marrow can cause anemia, since that tissue is the site of erythrocyte synthesis. Bone marrow destruction can also be caused by irradiation, disease, or various chemical agents. In cases of renal dysfunction, the severity of the associated anemia correlates highly with the extent of the dysfunction; it is treated with genetically engineered erythropoietin.

Anemias

ANEMIAS

DEFINITION


Anemia is a condition characterized by abnormally low levels of red blood cells.

DESCRIPTION


Cells require a constant supply of oxygen in order to stay healthy. Oxygen is delivered to cells by red blood cells, which pick up oxygen in the lungs. They carry the oxygen to cells through the bloodstream.

The oxygen-carrying molecule in red blood cells is hemoglobin (pronounced HEE-muh-glo-bin). Hemoglobin is a large, complex molecule. It contains an atom of iron at its center. Iron attaches itself easily to oxygen atoms. It is the iron in hemoglobin that actually carries oxygen to cells.

Anemia develops when the body has an insufficient supply of red blood cells and hemoglobin. When that happens, cells do not get the oxygen they need and begin to die off. A variety of medical problems may develop.

Types of Anemia

More than four hundred different kinds of anemia have been identified. Many of them are rare. Some are mild medical problems, while others are moderate or serious. Some are so serious that they may cause death. A few of the most common forms of anemia include the following.

IRON DEFICIENCY ANEMIA. Iron deficiency anemia is the most common form of anemia in the world. In the United States the condition primarily affects young children and women. About 240,000 children between the ages of one and two have the condition. About 3.3 million women of child-bearing age have iron deficiency anemia.

The onset (beginning) of iron deficiency anemia is gradual. There may be no symptoms at first. As the name suggests, iron deficiency anemia occurs when the body does not have enough iron to make all the red blood cells it needs. Red blood cells die off faster than they can be made by the body.

FOLIC ACID DEFICIENCY ANEMIA. Folic acid is a member of the vitamin B family. It is used in the production of new red blood cells. Some people do not get enough folic acid in their normal diet, so their bodies are unable to produce enough red blood cells. In other cases, the body may not be able to properly use the folic acid eaten.

Anemias: Words to Know

Aplastic:
Having incomplete or faulty development.
Diabetes mellitus:
A medical disorder caused by the inability of a person's cells to use sugar correctly.
Hemoglobin:
A molecule found in red blood cells that contains an iron atom and that helps transport oxygen from the lungs to cells throughout the body.

Folic acid deficiency anemia occurs most often in infants and teenagers. Some important sources of folic acid are cheese, eggs, fish, green vegetables, meat, milk, and yeast. Smoking can also interfere with the body's ability to use folic acid.

VITAMIN B12 DEFICIENCY ANEMIA. Like folic acid, vitamin B12 is used to make red blood cells. The vitamin is found in meat and vegetables. Some symptoms of vitamin B12 deficiency anemia are loss of muscle control, loss of feeling in the arms and legs, soreness of the tongue, and weight loss.

The most common form of vitamin B12 deficiency anemia is called pernicious anemia. People between the ages of fifty and sixty are at highest risk for pernicious anemia. Some conditions that can lead to pernicious anemia are eating disorders (see anorexia nervosa and bulimia entries), poor nutrition, diabetes mellitus (pronounced DI-uh-BEE-teez MEH-luh-tuss; see diabetes mellitus entry), stomach problems, and thyroid disease.

HEMOLYTIC ANEMIA. Hemolytic (pronounced HEE-muh-lit-ik) anemia occurs when red blood cells are destroyed faster than they are made. In some cases, an infection can cause this problem. In other cases, the body's own immune system destroys the red blood cells. Some symptoms of hemolytic anemia include pain, shock, gallstones, an enlarged spleen, and other serious health problems.

THALASSEMIAS. Thalassemias (pronounced thal-uh-SEE-mee-uhs) are caused by the body's inability to manufacture enough red blood cells. The condition is a genetic disorder, meaning that parents who have a gene for the condition may pass it to their children. Genes are chemical units in the body that tell cells what functions to perform. In people who have defective thalassemia genes, cells have lost the instructions needed to produce red blood cells.

AUTOIMMUNE HEMOLYTIC ANEMIAS. An autoimmune disorder is one in which a person's immune system attacks its own body. The normal function of the immune system is to protect the body against foreign invaders, such as bacteria and viruses. But the immune system can sometimes become confused. It thinks that parts of the body are a foreign invader. In the case of autoimmune hemolytic anemias, the immune system attacks red blood cells, killing them just as it would destroy bacteria or viruses.

SICKLE CELL ANEMIA. Sickle cell anemia (see sickle cell anemia entry) is a genetic disorder. Cells receive genes that give them the wrong instructions for making red blood cells. Red blood cells are normally shaped like plump doughnuts. In sickle cell anemia, the cells are curved with sharp points. These cells easily stick to each other. They also stick to the walls of blood vessels. Clumps of sickled red blood cells can collect in a vein or artery and block it. This condition can cause pain, weakness, and, in extreme cases, death.

APLASTIC ANEMIA. Aplastic anemia is a serious form of anemia that can lead to death. The body makes too few of all kinds of blood cells: red blood cells, white blood cells, and platelets (pronounced PLATE-lits). Platelets are blood cells that help blood to clot. Aplastic anemia may be caused by a recent severe illness, long-term exposure to industrial chemicals, and the use of certain types of medication.

CAUSES


Anemia is caused primarily by one of three conditions. The first is bleeding. Bleeding results in the loss of red blood cells from the body. The second condition is a decreased rate of red blood cell production. Red blood cells are not produced as fast as they die off. The third condition is an increased rate of red blood cell destruction. Red blood cells die off faster than they can be replaced by the body.

Of these factors, bleeding is the most common cause of anemia. Bleeding can be a chronic or acute problem. A chronic problem is one that lasts for a long period of time. An acute problem is one that comes on suddenly and is quite severe. Some common causes of chronic bleeding include:

  • Cancer (see cancer entry)
  • Gastrointestinal (digestive system) tumors
  • Other diseases and disorders of the digestive system
  • Heavy menstrual flow
  • Hemorrhoids
  • Nosebleeds
  • Stomach ulcers (see ulcer entry)
  • Long-term alcohol abuse (see alcoholism entry)

Acute blood loss is usually the result of:

  • Childbirth
  • Injury
  • A ruptured blood vessel
  • Surgery

SYMPTOMS


Some common symptoms of mild anemia include weakness, fatigue, and a "run-down" feeling. Other signs include pale skin and a lack of color in the creases of the palm, gums, nail beds or lining of the eyelids. Someone who is weak, tires easily, is often out of breath, and feels faint or dizzy may have severe anemia. Other symptoms of anemia include:

  • Chest pain, often accompanied by a choking sensation
  • A strong desire to eat ice, paint, or dirt
  • Headache
  • Loss of memory or the ability to concentrate
  • Inflammation of the tongue or mouth
  • Insomnia (inability to sleep)
  • Irregular heartbeat
  • Loss of appetite
  • Nails that are dry, brittle, or ridged
  • Rapid breathing
  • Sores in the mouth, throat, or rectum
  • Sweating
  • Swelling of the hands and feet
  • Excessive thirst
  • Ringing in the ears
  • Unexplained bleeding or bruising

Additional symptoms related to pernicious anemia include:

  • Problems with movement or balance
  • Tingling in the hands and feet
  • Confusion, depression, and memory loss

DIAGNOSIS


The first step in diagnosing anemia is usually to take a medical history. Since some forms of anemia are inherited, a doctor will especially want to discover if the condition has occurred with other members of the family.

The best way of diagnosing anemia is with a blood test. A sample of the patient's blood is taken with a needle. The sample is then studied under a microscope. The number, size, and shape of red blood cells can then be determined. This information tells whether the patient has anemia and, if so, what kind.

MEETING YOUR NEEDS FOR IRON

Four groups of people have a greater-than-normal need for iron: infants, growing boys and girls, women who are menstruating, and pregnant women. Infants often lack iron because they drink primarily milk, and milk contains no iron. Growing boys and girls often don't get enough iron in their daily diet to keep up with their developing bodies. Menstruating women need extra iron because of the blood they lose during menstruation. And pregnant women lack sufficient iron because of the blood needed by their growing fetus.

These conditions are recognized in the U.S. government's Recommended Dietary Allowances (RDAs). An RDA is the amount of a vitamin or mineral that a person needs to take in each day in order to stay healthy. The RDA for iron for infants one year of age is 15 mg (milligrams) per day. This number drops to 10 mg a day for boys and girls between the ages of three and eleven. During the teen years, however, the RDA for iron increases to 18 mg per day.

That standard stays the same for women until they reach menopause (the period when menstruation stops). It then drops to 10 mg per day again. For pregnant women, however, the RDA ranges from 30 to 60 mg per day. It is during this period that the human body needs iron more than any other time in life.

Most people can get all the iron they need by choosing the right foods. Beef, kidney, liver, beans, clams, peaches, and soybeans are all rich in iron. But pregnant women find it nearly impossible to get enough iron from their diet. They usually have to take iron pills in order to avoid anemia.

TREATMENT


Treatment differs for each type of anemia. Iron deficiency, folic acid deficiency, and vitamin B12 deficiency anemias are all nutritional problems. That is, the patient is not getting enough of certain essential nutrients through his or her diet. Problems of this kind can often be solved with nutritional supplements. The patient may need to take vitamin or mineral supplements that provide the missing nutrient. Patients should also be sure to eat foods that contain the vitamins and minerals needed to prevent anemia, including:

  • Almonds
  • Broccoli
  • Dried beans
  • Dried fruits
  • Enriched breads and cereals
  • Lean red meat
  • Liver
  • Potatoes
  • Rice
  • Shellfish
  • Tomatoes

More serious forms of anemia may require surgery. Bleeding ulcers and certain types of stomach disorders are examples of anemias that may be treated surgically. In some cases, blood transfusions may be required. People who have lost large numbers of red blood cells may require a transfusion in order to avoid serious complications of anemia.

The most extreme form of treatment in such cases is a bone marrow transplant. All blood cells are made in bone marrow. Marrow is a fatty tissue found in the center of bones. People whose bodies make too few red blood cells may need a bone marrow transplant. Marrow from a healthy person is injected into the patient's bones. If successful, the healthy marrow begins producing red blood cells.

There is no cure for sickle cell anemia, autoimmune hemolytic anemia, and some other forms of anemia, therefore, treatment for these forms of anemia has two goals. First, steps should be taken to avoid complications. For example, a person with sickle cell anemia may require immunizations (shots) to protect against influenza, pneumonia, and other infectious diseases. Second, efforts should be made to relieve symptoms as much as possible. People with hemolytic anemia, for example, may be given shots of corticosteroids (pronounced kor-tih-ko-STIHR-oids), which help reduce inflammation and swelling that often accompany this condition.

Alternative Treatment

Practitioners often follow traditional medical treatments in dealing with anemia. That is, they may recommend nutritional supplements to replace lost iron or to improve general health. Certain iron-rich herbs may also be recommended. These herbs include yellow dock root, dandelion, parsley, and nettle.

Herbs may also be suggested to improve digestion. Improved digestion ensures that iron in foods is more likely to be absorbed by the body. Some herbs recommended for this purpose include gentian, anise, caraway, cumin, linden, and licorice.

Traditional Chinese treatments for anemia include:

  • Acupuncture, which is a therapy technique where fine needles puncture the body, to improve the health of the spleen
  • Asian ginseng, to restore energy
  • Dong quai, an herb used to control heavy menstrual bleeding
  • A mixture of dong quai and Chinese foxglove, to clear a pale complexion

PROGNOSIS


Prognosis differs for various kinds of anemia. Deficiency anemias usually improve after three to six weeks of treatment. Patients should continue taking supplements for six months to make sure the body has enough iron. Periodic tests may be necessary to make sure that the anemia has not returned.

Pernicious anemia cannot be cured. However, its symptoms can be treated with regular shots of vitamin B12. This treatment usually works very quickly, often within a matter of minutes. There is also no cure for sickle cell anemia. Many patients, however, are able to lead reasonably normal lives with proper treatment.

Aplastic anemia can sometimes be cured with a bone marrow transplant. Thalassemias usually require no treatment. People are able to live normal lives with all but the most severe forms of the disease.

PREVENTION


Inherited forms of anemia cannot be prevented. Parents can often find out if they carry the genes for anemia. With this information, they can decide if they want to have children and pass those genes on to them.

Eating a well-balanced diet and avoiding excessive amounts of alcohol is a simple method to protect against deficiency forms of anemia. To be safe, a person can take nutritional supplements to ensure that he or she is getting enough iron.

Some methods of preventing specific types of anemia include:

  • Avoiding lengthy exposure to industrial chemicals and drugs known to cause aplastic anemia
  • Not taking medications or eating foods that may cause hemolytic anemia
  • Receiving regular B12 shots to prevent pernicious anemia

See also: Sickle cell anemia.

FOR MORE INFORMATION


Books

Beshore, George W., ed. Sickle Cell Anemia. New York: Franklin Watts, 1994.

Uthman, Ed. Understanding Anemia. Jackson: University Press of Mississippi, 1998.

Organizations

Aplastic Anemia Foundation of America. P.O. Box 613, Annapolis, MD 21404. (800) 7472620. http://www.aplastic.org.

anaemia

anaemia (ă-nee-miă) n. a reduction in the quantity of the oxygen-carrying pigment haemoglobin in the blood. The main symptoms are excessive tiredness and fatigability, breathlessness on exertion, pallor, and poor resistance to infection. The many causes of anaemia include loss of blood (haemorrhagic a.); lack of iron (iron-deficiency a.); the increased destruction of red blood cells (haemolytic a.); and the impaired production of red blood cells (see aplastic anaemia, leukaemia, pernicious (anaemia)). Anaemias can be classified on the basis of the size of the red cells, which may be large (macrocytic a.), small (microcytic a.), or normal-sized (normocytic a.).
anaemic adj.

anaemia

anaemia A condition that arises when either there are too few erythrocytes (red blood cells), the erythrocytes do not contain sufficient amounts of haemoglobin, or the erythrocytes are abnormal in other respects. Anaemia often results from loss of blood or from a deficiency in the factors necessary to synthesize haemoglobin (e.g. iron) or erythrocytes (e.g. folic acid and vitamin B12). Increased destruction of erythrocytes may be induced by certain drugs or severe infection, and an abnormal form of haemoglobin results in sickle-cell anaemia (see polymorphism).

Anemia

Anemia

Carries Story

What Is Anemia?

How Is Blood Made in a Healthy Person?

What Is Different in a Person with Anemia?

What Are the Different Types of Anemia?

First Category: Anemia from Blood Loss

Second Category: Decreased Production of Red Blood Cells

Third Category: Hemolytic Anemias

How Do People Know If They Are Anemic?

Doctors as Detectives: Diagnosing Anemia

Scientific Research

Resources

Anemia is a condition that occurs when there are too few properly functioning red bloods cells to carry enough oxygen to the body. Anemia may have different underlying causes. Treatment of anemia depends on its cause and may involve dietary changes, medication, and blood transfusions.

KEYWORDS

for searching the Internet and other reference sources

Erythrocytes

Hematology

Hemoglobin

Hemolysis

Carries Story

When Carrie turned thirteen, she was determined to finally lose all of what she called her baby fat. She longed to look like the skinny models who graced the covers of the fashion magazines. Carrie stopped eating the well-balanced meals her mother made. Instead, she grabbed rice cakes or low-fat chips to stop the hunger pangs. At about the same time, Carrie got her period for the first time.

It was not long before Carrie started to feel lightheaded whenever she stood up, and in gym class she had to stop and rest every five minutes. Her gym teacher noticed Carries behavior and how pale she looked and suspected that Carrie had iron deficiency anemia. This type of anemia is very common in teenage girls because of poor eating habits and iron loss due to menstruation.* At the coachs suggestion, Carrie visited her doctor. Together Carrie and her doctor came up with a healthy diet and exercise plan to help Carrie reach an appropriate weight and keep her iron level normal.

* menstruation
(men-stroo-A-shun) is the discharge of bood and tissue through the vagina that occurs periodically to women of child-bearing age. Because it usually occurs at about four-week intervals, it is often called the monthly period.

What Is Anemia?

Anemia (a-NEE-me-a) is not a disease in itself. Instead, it is a sign that the body has a problem with its red blood cells. The blood of a person with anemia does not contain enough red blood cells or enough of the protein hemoglobin (he-mo-GLOW-bin). Anemia can develop because of poor nutrition, excessive blood loss, destruction of red blood cells, abnormal hemoglobin, or from a number of other causes. But no matter what causes anemia, the result is always the same: the blood does not carry enough oxygen to the cells throughout the body, so the body cannot function normally.

How Is Blood Made in a Healthy Person?

Blood consists of red blood cells, white blood cells, platelets, and plasma. Red blood cells, or erythrocytes (e-RITH-ro-sites), are the most numerous cells in the blood and give blood its red color. The tissues and cells in the body require oxygen to function properly, and erythrocytes are specialized to carry and distribute oxygen because they contain hemoglobin. Hemoglobin has the unique property of being able to absorb oxygen in the lungs, where it is plentiful, and release oxygen to the cells of the body, where it is needed. Hemoglobin consists of four protein molecules, called globins, and up to four heme molecules. The heme molecules are red-pigmented, nonprotein, iron-binding compounds, and they are responsible for binding to and transporting oxygen and carbon dioxide.

The U.S. and the World

UNICEF estimates that 2 billion of the worlds 6 billion people are iron deficient, which is one of the leading causes of anemia worldwide.

More than 50 percent of children under age 4 in developing nations are anemic, according to the World Health Organization.

An estimated 110,000 people worldwide died of anemia in 1998. About 95,000 of them lived in low- and middle-income nations.

In 1997, 4,471 people died of anemia in the United States. About 65 percent of them were 75 years or older.

A1995 estimate put the number of Americans with anemia at 4.1 million, including 2.5 million under age 45.

The death rate from anemia is about 42 percent higher for women than for men.

The death rate from anemia is almost 70 percent higher for people of African ancestry than for people of European ancestry.

In a healthy person, erythrocytes are produced by a process called hematopoiesis (he-ma-tow-po-EE-sis). Hematopoiesis takes place in the bone marrow, which is the tissue that fills the center of most bones. All blood cells originate from one type of cell in the marrow called a stem cell. As red blood cells are produced from stem cells and mature in the marrow, they begin to fill with hemoglobin. A healthy red blood cell contains about 300 hemoglobin molecules, and these take up most of its volume.

When erythrocytes mature, they also get rid of most of the normal components of cells (such as DNA, the nucleus, the endoplasmic reticulum, and the mitochondria). Without these components, erythrocytes cannot grow and divide, so they have a short life. Each cell survives for only about 120 days. The spleen, which is an oval organ located between the stomach and the diaphragm on the left side of the body, contains cells called macrophages (MAK-ro-fayj-ez). The macrophages engulf and break down the old, dying erythrocytes and recycle the iron from the hemoglobin molecules so that it can be used to make more hemoglobin. Every second, about 2 million erythrocytes die, and they must be replaced by hematopoiesis at exactly the same rate.

If the body detects a shortage of red blood cells, the kidneys make a hormone called erythropoietin (ee-rith-ro-po-EE-tin). This protein is secreted into the blood, which then signals the bone marrow to make more red blood cells.

Granny Heath and Liver Therapy

Before and during the early twentieth century, the ingestion of great amounts of liver served as an effective means for preventing and treating most types of anemia.

In My Second Life (1944), author and physician Thomas Hall Shastid recalls his school teacher Granny Heath, who advocated that, cooked or raw, the liver of just about any farm animal was the perfect remedy for what she called the littleness of blood.

Medical history records that Dr. George R. Minot (1885-1950), Dr. William Parry Murphy (b. 1892), and Dr. George Hoyt Whipple (1878-1976) were the actual creators of the first effective treatment for pernicious anemia using liver. They were awarded the Nobel Prize in 1934 for their research on blood chemistry and histology, which established the scientific basis for successful use of liver therapy.

What Is Different in a Person with Anemia?

Blood production is a complex process that requires communication between many parts of the body, including the bone marrow, the kidneys, and the spleen. There are many places in the process where something can go wrong. Problems with stem cells, replication and maturation of erythrocytes, the manufacture of hemoglobin, improper signaling between the kidney and bone marrow (erythropoietin), and problems with spleen function (destruction of cells by macrophages) can result in anemia. A person can have anemia because of an inherited blood disorder, because of a blood condition he or she acquired somehow, and even because of diseases not directly related to the blood.

There are several dozen types of anemia that are categorized by their underlying cause. When doctors test blood for anemia, they often describe the blood by the hemoglobin content of red blood cells (color) and by the size and shape of red blood cells. These descriptions can point a doctor toward the underlying disorder. Treatment is specific for each type of anemia and is based on treating the underlying disease.

What Are the Different Types of Anemia?

There are three broad categories of causes of anemia. First, when someone is injured and loses a great deal of blood, anemia can develop because the bodys total blood volume is lost faster than it can be replaced. In the second category, the process of making red blood cells in the body is not working normally: bone marrow does not make enough erythrocytes, the erythrocytes do not contain enough hemoglobin, or the hemoglobin does not function correctly. In the third category, red blood cells are destroyed faster than the marrow can replenish them. Some of the most common types of anemia in each category are described below.

First Category: Anemia from Blood Loss

People who lose a lot of blood very quickly, like those who have been injured in an accident, had a blood vessel burst, or have lost blood during surgery, can become anemic because the body cannot make blood as fast as it is being lost. In cases where blood loss is life threatening, a person can have the lost blood replaced through a blood transfusion*. In less severe cases, the body will slowly bring the blood volume and hemoglobin content back to normal by itself. In fact, a person can lose two-thirds of his or her blood volume over a 24-hour period without dying. Other people have a place in their body that is constantly bleeding a little bit, such as a wound in the skin or mucous membranes inside the body (ulcer). In these cases, the source of bleeding needs to be found and treated, and dietary supplements of iron often are needed to help boost hemoglobin production.

* blood transfusion
is the process of giving blood (or certain cells or chemicals found in the blood) to a person who needs it.

Second Category: Decreased Production of Red Blood Cells

Anemias caused by a decreased production of red blood cells are also called hypoplastic anemias, and many different conditions and disorders can cause this kind of anemia.

Nutritional causes

Certain important vitamins and minerals, such as iron, vitamin B12, and folic acid, are necessary for the bone marrow to make hemoglobin and erythrocytes. If these elements are missing from the diet or are not absorbed from the diet, anemia can develop. Adding food rich in these elements or adding supplements to the diet helps replenish the blood supply.

Iron deficiency anemia occurs when a person does not eat enough foods containing iron or when the body has problems absorbing iron. A low iron level in the body means that there is not enough iron available to make hemoglobin, which results in decreased production of red blood cells. This is a very common type of anemia, especially in infants and teenagers, who need lots of iron to fuel growing bodies. Also, 30-50% of American women are at risk for anemia because of blood loss during menstruation and inadequate amounts of iron in their diets to offset these monthly losses. Iron deficiency anemia is characterized by small red blood cells.

Pernicious anemia occurs when a person does not eat enough foods containing vitamin B12 or is unable to absorb B12 properly. To absorb vitamin B12, the lining of the stomach must produce hydrochloric acid and make a chemical that scientists call intrinsic factor. If acid production is decreased or intrinsic factor is missing, the vitamin cannot be absorbed. This type of anemia usually affects adults between the ages of 50 and 60, but it is rare in African American and Asian people. People with a poor diet, bulimia, anorexia nervosa, diabetes, or thyroid disease, or who have had stomach surgery, stomach cancer, or a family history of pernicious anemia are prone to this problem. It usually develops gradually, so the symptoms are hard to detect.

Genetic causes

Sometimes people are born with diseases that diminish the bodys ability to produce red blood cells. Thalassemia (thal-a-SEE-me-a) and sideroblastic (sid-er-o-BLAS-tik) anemia both occur because the bone marrow cannot produce hemoglobin normally.

Thalassemia is an inherited disorder in which the rate of hemoglobin production is too low. In this condition, the globin portion of hemoglobin is defective. This disorder is most common in people of Mediterranean, African, and Asian ancestry. Thalassemia is divided into two categories: major and minor. People born with thalassemia major have severe anemia during the first year of life that results in slow growth, abnormal bone development, and an enlarged liver and spleen. People with thalassemia minor often do not have any symptoms.

In sideroblastic anemia, the heme molecule of hemoglobin is not made correctly. This problem can be a genetic disorder, but it also can occur in people suffering from alcoholism, people exposed to toxins such as lead, or people who have acquired bone marrow disorders.

Aplastic anemia and bone marrow disorders

Aplastic anemia describes a category of anemias in which the hematopoietic (blood-forming) cells of the bone marrow are destroyed. In many cases, doctors do not know why these cells have been destroyed. In other cases, the blood-forming cells are destroyed by cancer of the bone marrow or by exposure to toxic chemicals, radiation, certain antibiotics, or other medications. A bone marrow transplant from an identical twin or from a relative with compatible cell types can be used to treat aplastic anemia, but it is often difficult to find a donor with the right cell type. Finding treatment for aplastic anemia is an active field of research.

Infection and other disorders

People who frequently are ill with infections are prone to anemia because the infection causes the production of red blood cells to slow down. Anemia is very common in people with AIDS because their immune systems* do not function normally and they are prone to infections. People who have diseases of their kidneys often develop anemia because the kidneys no longer respond to decreases in red blood cells by producing enough erythropoietin.

* immune system
fights germs and other foreign substances that enter the body.

Third Category: Hemolytic Anemias

Hemolytic anemias are caused by the premature destruction of red blood cells. Erythrocytes can be destroyed too quickly or too early because of infection, because the hemoglobin produced is abnormal, because the spleen does not function properly, or because a person has been exposed to certain drugs or toxic chemicals. Red blood cells can have defects in the membrane that surrounds them, which leads to their destruction by macrophages. Hemolytic anemia also can be caused by problems with the immune system.

Sickle cell anemia and genetic causes

Sickle cell anemia is the most well-known type of hemolytic anemia. It is a genetic disease, meaning that a person inherits the genes* for the condition from his or her parents. If the person received only one copy of the affected gene (from one parent), he or she is said to have the sickle cell trait. A person who received the gene from both parents will have sickle cell disease. This type of anemia occurs most frequently in people of African ancestry. In the United States, 0.3% of the African-American population (over 50,000 people) has this disorder. People with sickle cell disease frequently have severe anemia, episodes of pain, delayed growth, and increased infections. People with sickle cell trait usually have no symptoms of anemia and grow and develop normally.

* genes
are the material in the body that helps determine physical and mental characteristics, such as whether a person has brown hair or blue eyes.

In a person with sickle cell anemia, the hemoglobin is different from that in healthy erythrocytes and it causes the red blood cells to be shaped like crescents. Because of this shape, they cannot easily flow through the bloodstream and they are destroyed faster than the body can replace them.

Autoimmune diseases

People with autoimmune diseases, such as rheumatoid arthritis, can develop hemolytic anemia. In autoimmune diseases, the bodys immune system does not work correctly. In addition to destroying foreign cells, such as bacteria that cause infection, the abnormal immune system attacks and destroys its own cells, including erythrocytes. In some people, drugs that reduce the immune systems activity (immunosuppressives) are used to treat anemia.

What Do Babies and Teenage Girls Have in Common?

Infants and teenage girls are at risk of developing iron-deficiency anemia. Teenage girls are at risk because they lose blood when they begin to menstruate and because they are undergoing growth spurts. These factors combined with an iron-poor diet (many teenage girls are concerned about their weight and how they look, so they go on diets that do not provide enough iron) often result in anemia.

Babies need lots of iron to fuel their rapid growth; their blood volume is expanding as quickly as the rest of their body is growing. Many doctors test 6- to 12-month-old babies for anemia, even if they seem to be happy and healthy, because historically, many babies developed iron-deficiency anemia between these ages. Today, only 2 to 3 percent of middle class infants develop anemia, and this is largely due to the iron added to baby formula and baby cereals. For breastfed babies, the iron in cereal or in supplements is especially important, because breast milk cannot provide enough iron. For older children and adults, adding a food with vitamin C, such as oranges, cantaloupe, or broccoli, helps the body to absorb the iron. Unfortunately, the rates of anemia are higher in poor communities because of poor nutrition.

How Do People Know If They Are Anemic?

People who have mild anemia often have no symptoms. For people with more severe anemia, how they feel depends on how old they are, how fast the anemia developed, and what other illnesses they might have. If the anemia develops rapidly, a person is more likely to be aware of symptoms. If it develops over a long period of time, even people with moderate anemia may have few obvious symptoms.

Like Carrie, people with moderate to severe anemia may feel tired, weak, dizzy, and short of breath, all because the cells of the body are not getting enough oxygen. This lack of oxygen can cause them to be irritable and lose interest in what is going on around them. Sometimes people with moderate to severe anemia look pale and waxy, and some people develop a yellow color to the skin (jaundice) because of excess destruction of their red blood cells. They can also experience headaches, loss of appetite, indigestion, a sore tongue, bleeding gums, insomnia (difficulty sleeping), a rapid heartbeat, fatigue, and poor concentration. Some women experience menstrual period irregularities.

Doctors as Detectives: Diagnosing Anemia

Dealing with anemia can be a complex process. Determining if a patient is anemic is easy, but finding the underlying cause can be more difficult.

To test for anemia, a doctor usually orders a complete blood count (CBC). A technician or nurse takes a small sample of blood. The blood is tested for the amount of hemoglobin it contains and the numbers and volume of the different types of blood cells. Some of the blood also is smeared onto a slide so that the size of the cells can be measured and the color and shape of the blood can be gauged.

Once anemia has been confirmed, the doctor has to become a detective. The doctor finds clues by examining the patient and by asking the patient and his or her family about their medical history. Here are some of the questions the doctor may ask:

  • What are your symptoms, when did they start, and how long have they lasted?
  • Do other people in your family have anemia?
  • What illnesses have you had recently?
  • What do you eat in your diet?
  • Have you recently bled a lot?
  • What drugs/medications have you taken recently?

Almost all cases of anemia can be identified by laboratory tests along with the patients history and a physical examination.

Because the marrow is where blood cells are made, and it is here that many problems can occur, in a few cases a bone marrow sample may be needed in order to find the cause of the anemia. In this procedure, a needle is inserted into the hip bone to obtain a sample of bone marrow. It is then analyzed for the types and activities of the cells.

Eating Right to Prevent Anemia

Good nutrition plays a big part in preventing or treating many types of anemia. A healthy diet should include eating foods every day that contain:

  • Vitamin B12: meat, fish, and dairy (this vitamin is only found in animal products).
  • Folic acid: dark green leafy vegetables, meat, eggs, orange juice, and whole-grain cereals.
  • Iron: beef; molasses; carob; collards, kale, and turnip greens; dried fruit; dried peas and beans; egg yolks; liver; oysters; potatoes in their skin; pumpkin; sardines; soy flour; spinach; wheat germ; whole grains; iron-fortified cereals.

Anemia is the bodys way of saying that something is wrong, and it should never be ignored. The doctor should always search for the underlying cause of anemia.

Scientific Research

Treatment of anemia depends entirely on the cause. Anemia gets a lot of scientific attention because it is a sign of so many different diseases and disorders. Research is focused both on better ways to diagnose anemia and on developing new ways to treat it. In some cases, anemia is difficult or impossible to treat.

For anemias caused by excessive or chronic bleeding, stopping blood loss is the first step. In some cases, a blood transfusion is used to replenish the volume of blood in the body. For people with dietary causes of anemia, eating a diet rich in the deficient nutrient or taking supplements such as iron or vitamins often fixes the problem.

Treatment for other anemias is more complex. For people with hemolytic anemias, finding out why the red blood cells are being destroyed prematurely is essential. In some people, the spleen must be removed to stop the premature destruction of erythrocytes.

One method of treating certain anemias caused by decreased production of red blood cells is to supply the body with erythropoietin (EPO). Different research groups have manufactured EPO to treat anemias caused by rheumatoid arthritis, HIV, kidney disease, and cancer. Other drugs are aimed at stimulating red cell production in people with sickle cell disease and some types of thalassemia.

See also

Fainting (Syncope)

Resources

Books

Bloom, Miriam. Understanding Sickle-Cell Disease. University Press of Mississippi, 1995.

Davies, Jill. Anemia: A Guide to Causes, Treatment and Prevention. Thorsons Publishers, 1994.

Davies, Jill. Recipes for Health: Anemia. Thorsons Publishers, 1995.

Uthman, Ed. Understanding Anemia. University Press of Mississippi, 1998.

Walker, Dava Jo, Van Wright, Cornelius and Hu, Ying-Hwa. Puzzles. Lollipop Press, 1996. (This is a childrens book about a 9-year-old girl with sickle-cell anemia.)

Organizations

Aplastic Anemia Foundation of America (AAFA, Inc.), P.O. Box 613, Annapolis, MD 21404. The AAFA provides emotional support, patient assistance, funds for research, and educational material about anemia. Telephone 800-747-2820 http://medic.med.uth.tmc.edu/ptnt/00001045.htm

Did You Know?

Cooking acidic foods like tomatoes in cast iron skillets or pans can add significant amounts of iron to the diet.

Sickle Cell Association, Texas Gulf Coast, 2626 South Loop West, Suite 245, Houston, TX 77054. Telephone 713-666-0300 http://www.sicklecell-texas.org

anaemia

anaemia Condition in which there is a shortage of haemoglobin, the oxygen-carrying pigment contained in erythrocytes (red blood cells). Symptoms include weakness, pallor, breathlessness, faintness, palpitations, and lowered resistance to infection. It may be due to a decrease in the production of haemoglobin or red blood cells, excessive destruction of red blood cells, or blood loss. Worldwide, iron deficiency is the commonest cause of anaemia.

anaemia

anaemia A shortage of red blood cells, leading to pallor and shortness of breath, especially on exertion. Most commonly due to a dietary deficiency of iron, or excessive blood losses resulting in iron losses greater than can be met from the diet. Other dietary deficiencies can also result in anaemia, including deficiency of vitamin B12 or folic acid (megaloblastic anaemia), vitamin E (haemolytic anaemia), and rarely vitamin C or vitamin B6.

anemia

a·ne·mi·a / əˈnēmēə/ (Brit. a·nae·mi·a) • n. a condition marked by a deficiency of red blood cells or of hemoglobin in the blood, resulting in pallor and weariness.

anaemia

anaemia morbid lack of blood. XIX. — modL. — Gr. anaimíā, f. AN-2 + haîma blood.
Hence anaemic XIX.

anemia

anemia See anaemia

anaemia

anaemia •Grasmere • cashmere •Emyr, premier •macadamia, Mesopotamia •academia, anaemia (US anemia), Bohemia, Euphemia, hypoglycaemia, leukaemia (US leukemia), septicaemia (US septicemia), uraemia •bulimia, Ymir •arrhythmia • Vladimir • encomia •costumier • Windermere •Hermia, hyperthermia, hypothermia

anemia

anemia •Grasmere • cashmere •Emyr, premier •macadamia, Mesopotamia •academia, anaemia (US anemia), Bohemia, Euphemia, hypoglycaemia, leukaemia (US leukemia), septicaemia (US septicemia), uraemia •bulimia, Ymir •arrhythmia • Vladimir • encomia •costumier • Windermere •Hermia, hyperthermia, hypothermia