Hypoglycemia

Definition

The condition called hypoglycemia is literally translated as low blood sugar. Hypoglycemia occurs when blood sugar (or blood glucose) concentrations fall below a level necessary to properly support the body's need for energy and stability throughout its cells.

Description

Carbohydrates are the main dietary source of the glucose that is manufactured in the liver and absorbed into the bloodstream to fuel the body's cells and organs. Glucose concentration is controlled by hormones, primarily insulin and glucagon. Glucose concentration also is controlled by epinephrine (adrenalin) and norepinephrine, as well as growth hormone. If these regulators are not working properly, levels of blood sugar can become either excessive (as in hyperglycemia) or inadequate (as in hypoglycemia). If a person has a blood sugar level of 50 mg/dl or less, he or she is considered hypoglycemic, although glucose levels vary widely from one person to another.

Hypoglycemia can occur in several ways.

Drug-induced hypoglycemia

Drug-induced hypoglycemia, a complication of diabetes, is the most commonly seen and most dangerous form of hypoglycemia.

Hypoglycemia occurs most often in diabetics who must inject insulin periodically to lower their blood sugar. While other diabetics also are vulnerable to low blood sugar episodes, they have a lower risk of a serious outcome than insulin-dependant diabetics. Unless recognized and treated immediately, severe hypoglycemia in the insulin-dependent diabetic can lead to generalized convulsions followed by amnesia and unconsciousness. Death, though rare, is a possible outcome.

In insulin-dependent diabetics, hypoglycemia known as an insulin reaction or insulin shock can be caused by several factors. These include overmedicating with manufactured insulin, missing or delaying a meal, eating too little food for the amount of insulin taken, exercising too strenuously, drinking too much alcohol, or any combination of these factors.

Ideopathic or reactive hypoglycemia

Ideopathic or reactive hypoglycemia (also called postprandial hypoglycemia) occurs when some people eat. A number of reasons for this reaction have been proposed, but no single cause has been identified.

In some cases, this form of hypoglycemia appears to be associated with malfunctions or diseases of the liver, pituitary, adrenals, liver, or pancreas. These conditions are unrelated to diabetes. Children intolerant of a natural sugar (fructose) or who have inherited defects that affect digestion also may experience hypoglycemic attacks. Some children with a negative reaction to aspirin also experience reactive hypoglycemia. It sometimes occurs among people with an intolerance to the sugar found in milk (galactose), and it also often begins before diabetes strikes later on.

Fasting hypoglycemia

Fasting hypoglycemia sometimes occurs after long periods without food, but it also happens occasionally following strenuous exercise, such as running in a marathon.

Other factors sometimes associated with hypoglycemia include:

• pregnancy
• a weakened immune system
• a poor diet high in simple carbohydrates
• prolonged use of drugs, including antibiotics
• chronic physical or mental stress
• heartbeat irregularities (arrhythmias)
• allergies
• breast cancer
• high blood pressure treated with beta-blocker medications (after strenuous exercise)
• upper gastrointestinal tract surgery.

Causes and symptoms

When carbohydrates are eaten, they are converted to glucose that goes into the bloodstream and is distributed throughout the body. Simultaneously, a combination of chemicals that regulate how our body's cells absorb that sugar is released from the liver, pancreas, and adrenal glands. These chemical regulators include insulin, glucagon, epinephrine (adrenalin), and norepinephrine. The mixture of these regulators released following digestion of carbohydrates is never the same, since the amount of carbohydrates that are eaten is never the same.

Interactions among the regulators are complicated. Any abnormalities in the effectiveness of any one of the regulators can reduce or increase the body's absorption of glucose. Gastrointestinal enzymes such as amylase and lactase that break down carbohydrates may not be functioning properly. These abnormalities may produce hyperglycemia or hypoglycemia, and can be detected when the level of glucose in the blood is measured.

Cell sensitivity to these regulators can be changed in many ways. Over time, a person's stress level, exercise patterns, advancing age, and dietary habits influence cellular sensitivity. For example, a diet consistently overly rich in carbohydrates increases insulin requirements over time. Eventually, cells can become less receptive to the effects of the regulating chemicals, which can lead to glucose intolerance.

Diet is both a major factor in producing hypoglycemia as well as the primary method for controlling it. Diets typical of western cultures contain excess carbohydrates, especially in the form of simple carbohydrates such as sweeteners, which are more easily converted to sugar. In poorer parts of the world, the typical diet contains even higher levels of carbohydrates. Fewer dairy products and meats are eaten, and grains, vegetables, and fruits are consumed. This dietary trend is balanced, however, since people in these cultures eat smaller meals and usually use carbohydrates more efficiently through physical labor.

Early symptoms of severe hypoglycemia, particularly in the drug-induced type of hypoglycemia, resemble an extreme shock reaction. Symptoms include:

• cold and pale skin
• numbness around the mouth
• apprehension
• heart palpitations
• emotional outbursts
• hand tremors
• mental cloudiness
• dilated pupils
• sweating
• fainting

Mild attacks, however, are more common in reactive hypoglycemia and are characterized by extreme tiredness. Patients first lose their alertness, then their muscle strength and coordination. Thinking grows fuzzy, and finally the patient becomes so tired that he or she becomes "zombie-like," awake but not functioning. Sometimes the patient will actually fall asleep. Unplanned naps are typical of the chronic hypoglycemic patient, particularly following meals.

Additional symptoms of reactive hypoglycemia include headaches, double vision, staggering or inability to walk, a craving for salt and/or sweets, abdominal distress, premenstrual tension, chronic colitis, allergies, ringing in the ears, unusual patterns in the frequency of urination, skin eruptions and inflammations, pain in the neck and shoulder muscles, memory problems, and sudden and excessive sweating.

Unfortunately, a number of these symptoms mimic those of other conditions. For example, the depression, insomnia, irritability, lack of concentration, crying spells, phobias, forgetfulness, confusion, unsocial behavior, and suicidal tendencies commonly seen in nervous system and psychiatric disorders also may be hypoglycemic symptoms. It is very important that anyone with symptoms that may suggest reactive hypoglycemia see a doctor.

Because all of its possible symptoms are not likely to be seen in any one person at a specific time, diagnosing hypoglycemia can be difficult. One or more of its many symptoms may be due to another illness. Symptoms may persist in a variety of forms for long periods of time. Symptoms also can change over time within the same person. Some of the factors that can influence symptoms include physical or mental activities, physical or mental state, the amount of time passed since the last meal, the amount and quality of sleep, and exercise patterns.

Diagnosis

Drug-induced hypoglycemia

Once diabetes is diagnosed, the patient then monitors his or her blood sugar level with a portable machine called a glucometer. The diabetic places a small blood sample on a test strip that the machine can read. If the test reveals that the blood sugar level is too low, the diabetic can make a correction by eating or drinking an additional carbohydrate.

Reactive hypoglycemia

Reactive hypoglycemia only can be diagnosed by a doctor. Symptoms usually improve after the patient has gone on an appropriate diet. Reactive hypoglycemia was diagnosed more frequently 10-20 years ago than today. Studies have shown that most people suffering from its symptoms test normal for blood sugar, leading many doctors to suggest that actual cases of reactive hypoglycemia are quite rare. Some doctors think that people with hypoglycemic symptoms may be particularly sensitive to the body's normal postmeal release of the hormone epinephrine, or are actually suffering from some other physical or mental problem. Other doctors believe reactive hypoglycemia actually is the early onset of diabetes that occurs after a number of years. There continues to be disagreement about the cause of reactive hypoglycemia.

A common test to diagnose hypoglycemia is the extended oral glucose tolerance test. Following an overnight fast, a concentrated solution of glucose is drunk and blood samples are taken hourly for five to six hours. Though this test remains helpful in early identification of diabetes, its use in diagnosing chronic reactive hypoglycemia has lost favor because it can trigger hypoglycemic symptoms in people with otherwise normal glucose readings. Some doctors now recommend that blood sugar be tested at the actual time a person experiences hypoglycemic symptoms.

Treatment

Treatment of the immediate symptoms of hypoglycemia can include eating sugar. For example, a patient can eat a piece of candy, drink milk, or drink fruit juice. Glucose tablets can be used by patients, especially those who are diabetic. Effective treatment of hypoglycemia over time requires the patient to follow a modified diet. Patients usually are encouraged to eat small, but frequent, meals throughout the day, avoiding excess simple sugars (including alcohol), fats, and fruit drinks. Those patients with severe hypoglycemia may require fast-acting glucagon injections that can stabilize their blood sugar within approximately 15 minutes.

Alternative treatment

A holistic approach to reactive hypoglycemia is based on the belief that a number of factors may create the condition. Among them are heredity, the effects of other illnesses, emotional stress, too much or too little exercise, bad lighting, poor diet, and environmental pollution. Therefore, a number of alternative methods have been proposed as useful in treating the condition. Homeopathy, acupuncture, and applied kinesiology, for example, have been used, as have herbal remedies. One of the herbal remedies commonly suggested for hypoglycemia is a decoction (an extract made by boiling) of gentian (Gentiana lutea ). It should be drunk warm 15-30 minutes before a meal. Gentian is believed to help stimulate the endocrine (hormone-producing) glands.

In addition to the dietary modifications recommended above, people with hypoglycemia may benefit from supplementing their diet with chromium, which is believed to help improve blood sugar levels. Chromium is found in whole grain breads and cereals, cheese, molasses, lean meats, and brewer's yeast. Hypoglycemics should avoid alcohol, caffeine, and cigarette smoke, since these substances can cause significant swings in blood sugar levels.

Prevention

Drug-induced hypoglycemia

Preventing hypoglycemic insulin reactions in diabetics requires taking glucose readings through frequent blood sampling. Insulin then can be regulated based on those readings. Continuous glucose monitoring sensors have been developed to help diabetics remain more aware of possible hypoglycemic episodes. These monitors even can check for episodes while the patient sleeps, when many will experience severe hypoglycemia but not know it. Those who don't pay attention to severe hypoglycemia events or who have had previous severe hypoglycemia are the most likely to have future severe hypoglycemia. An audible alert can let the patient know immediately that he or she needs to take care of his or her blood sugar level. Continuous monitoring has proved particularly helpful in pediatric patients with Type 1 diabetes.

Maintaining proper diet also is a factor. Programmable insulin pumps implanted under the skin have proven useful in reducing the incidence of hypoglycemic episodes for insulin-dependent diabetics. As of late 1997, clinical studies continue to seek additional ways to control diabetes and drug-induced hypoglycemia. Tests of a substance called pramlintide indicate that it may help improve glycemic control in diabetics.

Reactive hypoglycemia

The onset of reactive hypoglycemia can be avoided or at least delayed by following the same kind of diet used to control it. While not as restrictive as the diet diabetics must follow to keep tight control over their disease, it is quite similar.

There are a variety of diet recommendations for the reactive hypoglycemic. Patients should:

• avoiding overeating
• never skipping breakfast
• including protein in all meals and snacks, preferably from sources low in fat, such as the white meat of chicken or turkey, most fish, soy products, or skim milk
• restricting intake of fats (particularly saturated fats, such as animal fats), and avoiding refined sugars and processed foods
• being aware of the differences between some vegetables, such as potatoes and carrots. These vegetables have a higher sugar content than others (like squash and broccoli). Patients should be aware of these differences and note any reactions they have to them.
• being aware of differences found in grain products. White flour is a carbohydrate that is rapidly absorbed into the bloodstream, while oats take much longer to break down in the body.
• keeping a "food diary." Until the diet is stabilized, a patient should note what and how much he/she eats and drinks at every meal. If symptoms appear following a meal or snack, patients should note them and look for patterns.

• eat fresh fruits, but restrict the amount they eat at one time. Patients should remember to eat a source of protein whenever they eat high sources of carbohydrate like fruit. Apples make particularly good snacks because, of all fruits, the carbohydrate in apples is digested most slowly.
• following a diet that is high in fiber. Fruit is a good source of fiber, as are oatmeal and oat bran. Fiber slows the buildup of sugar in the blood during digestion.

A doctor can recommend a proper diet, and there are many cookbooks available for diabetics. Recipes found in such books are equally effective in helping to control hypoglycemia.

Prognosis

Like diabetes, there is no cure for reactive hypoglycemia, only ways to control it. While some chronic cases will continue through life (rarely is there complete remission of the condition), others will develop into type II (age onset) diabetes. Hypoglycemia appears to have a higher-than-average incidence in families where there has been a history of hypoglycemia or diabetes among their members, but whether hypoglycemia is a controllable warning of oncoming diabetes has not yet been determined by clinical research.

A condition known as hypoglycemia unawareness can develop in those who do not control their blood glucose, particularly in people with Type 1 diabetes. These people may lose notice of the automatic warning symptoms of hypoglycemia that normally occur as their bodies become so used to frequent periods of hypoglycemia. It is not a permanent event, but can be treated by careful avoidance of hypoglycemia for about two weeks.

Resources

BOOKS

Ruggiero, Roberta. The Do's and Don'ts of Low Blood Sugar. Hollywood, FL: Frederick Fell Publishers.

PERIODICALS

Brauker, James, et al. "Use of Continuous Glucose Monitoring Alerts to Better Predict, Prevent and Treat Postprandial Hyperglycemia." Diabetes June 2003: 90-91.

Gertzman, Jerilyn, et al. "Severity of Hypoglycemia and Hypoglycemia Unawareness Are Associated with the Extent of Unsuspected Nocturnal Hypoglycemia." Diabetes June 2003:146-151.

Kumar, Rajeev, and Miles Fisher. "Impaired Hypoglycemia Awareness: Are we Aware?" Diabetes and Primary Care Summer 2004: 33-38.

Ludvigsson, Johnny, and Ragnar Hanas. "Continuous Subcutaneous Glucose Monitoring Improved Metabolic Control in Pediatric Patients With Type 1 Diabetes: A Controlled Crossover Study." Pediatrics May 2003: 933-936.

ORGANIZATIONS

Hypoglycemia Association, Inc. 18008 New Hampshire Ave., PO Box 165, Ashton, MD 20861-0165.

National Hypoglycemia Association, Inc. PO Box 120, Ridgewood, NJ 07451. (201) 670-1189.

KEY TERMS

Adrenal glands— Two organs that sit atop the kidneys; these glands make and release hormones such as epinephrine.

Epinephrine— Also called adrenalin, a secretion of the adrenal glands (along with norepinephrine) that helps the liver release glucose and limits the release of insulin. Norepinephrine is both a hormone and a neurotransmitter, a substance that transmits nerve signals.

Fructose— A type of natural sugar found in many fruits, vegetables, and in honey.

Glucagon— A hormone produced in the pancreas that raises the level of glucose in the blood. An injectable form of glucagon, which can be bought in a drug store, is sometimes used to treat insulin shock.

Postprandial— After eating or after a meal.

Hypoglycemia

Definition

The condition called hypoglycemia is literally translated as low blood sugar. Hypoglycemia occurs when blood sugar (or blood glucose) concentrations fall below a level necessary to properly support the body's need for energy and stability throughout its cells.

Description

Carbohydrates are the main dietary source of the glucose that is manufactured in the liver and absorbed into the bloodstream to fuel the body's cells and organs. Glucose concentration is controlled by hormones, primarily insulin and glucagon. Glucose concentration is also controlled by epinephrine (adrenalin) and norepinephrine, as well as growth hormone. If these regulators are not working properly, levels of blood sugar can become either excessive (as in hyperglycemia) or inadequate (as in hypoglycemia). If a person has a blood sugar level of 50 mg/dl or less, he or she is considered hypoglycemic, although glucose levels vary widely from one person to another.

Hypoglycemia can occur in several ways.

Drug-induced hypoglycemia

Drug-induced hypoglycemia, a complication of diabetes, is the most commonly seen and most dangerous form of hypoglycemia.

Hypoglycemia occurs most often in diabetics who must inject insulin periodically to lower their blood sugar. While other diabetics are also vulnerable to low blood sugar episodes, they have a lower risk of a serious outcome than do insulin-dependent diabetics. Unless recognized and treated immediately, severe hypoglycemia in the insulin-dependent diabetic can lead to generalized convulsions followed by amnesia and unconsciousness. Death, though rare, is a possible outcome.

In insulin-dependent diabetics, hypoglycemia known as an insulin reaction or insulin shock can be caused by several factors. These include overmedicating with manufactured insulin, missing or delaying a meal, eating too little food for the amount of insulin taken, exercising too strenuously, drinking too much alcohol, or any combination of these factors.

Idiopathic or reactive hypoglycemia

Idiopathic or reactive hypoglycemia (also called postprandial hypoglycemia) occurs when some people eat. A number of reasons for this reaction have been proposed, but no single cause has been identified.

In some cases, this form of hypoglycemia appears to be associated with malfunctions or diseases of the liver, pituitary, adrenals, liver, or pancreas. These conditions are unrelated to diabetes. Children intolerant of a natural sugar (fructose) or who have inherited defects that affect digestion may also experience hypoglycemic attacks. Some children with a negative reaction to aspirin also experience reactive hypoglycemia. It sometimes occurs among people with an intolerance to the sugar found in milk (galactose), and it also often begins before the onset of diabetes.

Fasting hypoglycemia

Fasting hypoglycemia sometimes occurs after long periods without food, but it also happens occasionally following strenuous exercise , such as running in a marathon.

Other factors sometimes associated with hypoglycemia include:

• pregnancy
• a weakened immune system
• a poor diet high in simple carbohydrates
• prolonged use of drugs, including antibiotics
• chronic physical or mental stress
• heartbeat irregularities (arrhythmias)
• allergies
• breast cancer
• high blood pressure treated with beta-blocker medications (after strenuous exercise)
• upper gastrointestinal tract surgery

Causes & symptoms

When carbohydrates are eaten, they are converted to glucose that goes into the bloodstream and is distributed throughout the body. Simultaneously, a combination of chemicals that regulate how the body's cells absorb that sugar is released from the liver, pancreas, and adrenal glands. These chemical regulators include insulin, glucagon, epinephrine (adrenaline), and norepinephrine. The mixture of these regulators released following digestion of carbohydrates is never the same, since the amount of carbohydrates that are eaten is never the same.

Interactions among the regulators are complicated. Any abnormalities in the effectiveness of any one of the regulators can reduce or increase the body's absorption of glucose. Gastrointestinal enzymes such as amylase and lactase that break down carbohydrates may not be functioning properly. These abnormalities may produce hyperglycemia or hypoglycemia, and can be detected when the level of glucose in the blood is measured.

Cell sensitivity to these regulators can be changed in many ways. Over time, a person's stress level, exercise patterns, advancing age, and dietary habits influence cellular sensitivity. For example, a diet consistently overly rich in carbohydrates increases insulin requirements over time. Eventually, cells can become less receptive to the effects of the regulating chemicals, which can lead to glucose intolerance.

Diet is both a major factor in producing hypoglycemia as well as the primary method for controlling it. Diets typical of Western cultures contain excess refined carbohydrates, especially in the form of simple carbohydrates such as sweeteners, which are more easily converted to sugar. In poorer parts of the world, the typical diet contains even higher levels of carbohydrates. Fewer dairy products and meat are eaten, and grains, vegetables, and fruits are consumed. This dietary trend is balanced, however, since people in these cultures eat more complex carbohydrates, eat smaller meals, and usually use carbohydrates more efficiently through physical labor.

Early symptoms of severe hypoglycemia, particularly in the drug-induced type of hypoglycemia, resemble an extreme shock reaction. Symptoms include:

• cold and pale skin
• numbness around the mouth
• apprehension
• heart palpitations
• emotional outbursts
• hand tremors
• mental cloudiness
• dilated pupils
• sweating
• fainting

Mild attacks, however, are more common in reactive hypoglycemia and are characterized by extreme tiredness. Patients first lose their alertness, then their muscle strength and coordination. Thinking grows fuzzy, and finally the patient becomes so tired that he or she becomes "zombie-like," awake but not functioning. Sometimes the patient will actually fall asleep. Unplanned naps are typical of the chronic hypoglycemic patient, particularly following meals.

Additional symptoms of reactive hypoglycemia include headaches, double vision, staggering or an inability to walk, a craving for salt and/or sweets, abdominal distress, premenstrual tension, chronic colitis, allergies, ringing in the ears, unusual patterns in the frequency of urination, skin eruptions and inflammations, pain in the neck and shoulder muscles, memory problems, and sudden and excessive sweating.

Unfortunately, a number of these symptoms mimic those of other conditions. For example, the depression, insomnia , irritability, lack of concentration, crying spells, phobias , forgetfulness, confusion, unsocial behavior, and suicidal tendencies commonly seen in nervous system and psychiatric disorders may also be hypoglycemic symptoms. It is very important that anyone with symptoms that may suggest reactive hypoglycemia see a doctor.

Because all of its possible symptoms are not likely to be seen in any one person at a specific time, diagnosing hypoglycemia can be difficult. One or more of its many symptoms may be due to another illness. Symptoms may persist in a variety of forms for long periods of time. Symptoms can also change over time within the same person. Some of the factors that can influence symptoms include physical or mental activities, physical or mental state, the amount of time passed since the last meal, the amount and quality of sleep, and exercise patterns.

Diagnosis

Drug-induced hypoglycemia

Once diabetes is diagnosed, the patient then monitors his or her blood sugar level with a portable machine called a glucometer. The diabetic places a small blood sample on a test strip that the machine can read. If the test reveals that the blood sugar level is too low, the diabetic can make a correction by eating or drinking an additional carbohydrate.

Reactive hypoglycemia

Reactive hypoglycemia can be diagnosed only by a doctor. Symptoms usually improve after the patient has gone on an appropriate diet. Reactive hypoglycemia was diagnosed more frequently 10–20 years ago than today. Studies have shown that most people suffering from its symptoms test normal for blood sugar, leading many doctors to suggest that actual cases of reactive hypoglycemia are quite rare. Some doctors think that people with hypoglycemic symptoms may be particularly sensitive to the body's normal postmeal release of the hormone epinephrine, or are actually suffering from some other physical or mental problem. Other doctors believe reactive hypoglycemia is actually the early onset of diabetes that occurs after a number of years. There continues to be disagreement about the cause of reactive hypoglycemia.

A common test to diagnose hypoglycemia is the extended oral glucose tolerance test. Following an overnight fast, a concentrated solution of glucose is drunk and blood samples are taken hourly for five to six hours. Though this test remains helpful in early identification of diabetes, its use in diagnosing chronic reactive hypoglycemia has lost favor because it can trigger hypoglycemic symptoms in people with otherwise normal glucose readings. Some doctors now recommend that blood sugar be tested at the actual time a person experiences hypoglycemic symptoms.

Treatment

Treatment of the immediate symptoms of hypoglycemia can include eating sugar. For example, a patient can eat a piece of candy, drink milk, or drink fruit juice. Glucose tablets can be used by patients, especially those who are diabetic. Effective treatment of hypoglycemia over time requires the patient to follow a modified diet. Patients are usually encouraged to eat small but frequent meals throughout the day and, avoid excess simple sugars (including alcohol), fats, and fruit drinks.

One of the herbal remedies commonly suggested for hypoglycemia is a decoction (an extract made by boiling) of gentian (Gentiana lutea ). It should be drunk warm 15–30 minutes before a meal. Gentian is believed to help stimulate the endocrine (hormone-producing) glands.

In addition to the dietary modifications recommended above, people with hypoglycemia may benefit from supplementing their diet with chromium , which is believed to help improve blood sugar levels. Chromium is found in whole-grain breads and cereals, cheese, molasses, lean meats, and brewer's yeast . Eating oats can help stabilize blood sugar levels. Daily supplements of vitamin E are also recommended. People with hypoglycemia should avoid alcohol, caffeine , and cigarette smoke, since these substances can cause significant swings in blood sugar levels.

Allopathic treatment

Those patients with severe hypoglycemia may require fast-acting glucagon injections that can stabilize their blood sugar within approximately 15 minutes.

Prevention

Drug-induced hypoglycemia

Preventing hypoglycemic insulin reactions in diabetics requires taking glucose readings through frequent blood sampling. Insulin can then be regulated based on those readings. Maintaining proper diet is also a factor. Programmable insulin pumps implanted under the skin have proven useful in reducing the incidence of hypoglycemic episodes for insulin-dependent diabetics. In early 2002, scientists announced that a new therapy involving a synthetic insulin called insulin glargine in combination with one of several other short-acting insulins could provide a new alternative for diabetics at risk for hypoglycemia. The synthetic insulin combination acted safely in all patients, including children, and did not cause hypoglycemia like rapid-acting insulins.

Reactive hypoglycemia

The onset of reactive hypoglycemia can be avoided or at least delayed by following the same kind of diet used to control it. While not as restrictive as the diet diabetics must follow to keep tight control over their disease, it is quite similar.

There are a variety of diet recommendations for the reactive hypoglycemic. Patients should:

• Avoid overeating.
• Never skip breakfast.
• Include protein in all meals and snacks, preferably from sources low in fat, such as the white meat of chicken or turkey, most fish, soy products, or skim milk.
• Restrict intake of fats (particularly saturated fats, such as animal fats), and avoid refined sugars and processed foods.
• Keep a "food diary." Until the diet is stabilized, a patient should note what and how much he/she eats and drinks at every meal. If symptoms appear following a meal or snack, patients should note them and look for patterns.
• Eat fresh fruits, but restrict the amount eaten at one time. Patients should remember to eat a source of proteinwhenever they eat high sources of carbohydrate like fruit. Apples make particularly good snacks because, of all fruits, the carbohydrate in apples is digested most slowly.
• Follow a diet that is high in fiber. Fruit is a good source of fiber, as are oatmeal and oat bran, which slow the buildup of sugar in the blood during digestion.

A doctor can recommend a proper diet, and there are many cookbooks available for diabetics. Recipes found in such books are equally effective in helping to control hypoglycemia.

Expected results

Like diabetes, there is no cure for reactive hypoglycemia, only ways to control it. While some chronic cases will continue through life (rarely is there complete remission of the condition), others will develop into type II (adult-onset) diabetes. Hypoglycemia appears to have a higher-than-average incidence in families where there has been a history of hypoglycemia or diabetes among their members, but whether hypoglycemia is a controllable warning of oncoming diabetes has not yet been determined by clinical research.

Resources

BOOKS

Ruggiero, Roberta. The Do's and Don'ts of Low Blood Sugar. Hollywood, FL: Frederick Fell Publishers.

PERIODICALS

Hartnett, Terry. "Early Results Show Promise for Synthetic Insulin." Diabetes Week (March 18, 2002): 4.

ORGANIZATIONS

Hypoglycemia Association, Inc. 18008 New Hampshire Ave., PO Box 165, Ashton, MD 20861-0165.

National Hypoglycemia Association, Inc. PO Box 120, Ridge-wood, NJ 07451. (201) 670-1189.

Paula Ford-Martin

Teresa G. Odle

Hypoglycemia

Definition

Hypoglycemia is a condition characterized by low blood sugar, or abnormally low levels of glucose in the blood.

Description

Hypoglycemia (also known as a hypo, insulin shock, and a low) is brought on by abnormally low levels of glucose in the blood (i.e., 70 mg/dl or less). The condition is common among children with type 1 diabetes, but may also occur less frequently in children or teens with type 2 diabetes who are taking a sulfonylurea drug. An inadequate diet, improperly calculated insulin dose, minor illnesses, or excessive activity without adequate sustenance can contribute to the condition. If unchecked, hypoglycemia can lead to unconsciousness. In very rare cases, the victim may suffer a seizure.

A hypoglycemic child will appear irritable, sweaty, shaky, and confused and may complain of being very hungry. In most cases, a snack of quick-acting carbohydrates (e.g., juice or hard candy) will remedy the situation. Glucose tablets or gel can also be taken. A child who has lost consciousness due to hypoglycemia may require a glucagon shot to return blood sugar levels to normal.

Newborns of women with gestational, type 1, or type 2 diabetes during pregnancy may also experience hypoglycemia at birth, particularly if the mother's blood glucose levels were not well controlled in late pregnancy. High levels of maternal glucose cause the fetus to generate equally high levels of insulin to handle the over-load, and when the maternal glucose source is disconnected at birth with the cutting of the umbilical cord, all of that insulin causes the newborn's blood sugar levels to plummet. Intravenous administration of a glucose solution to the newborn can help re-establish normal blood sugar levels.

A rare type of hypoglycemia, known as reactive hypoglycemia, may occur in children and teens without diabetes. In reactive hypoglycemia, blood glucose levels drop to 70 mg/dl approximately four hours after a meal is eaten, causing the same symptoms of low blood sugars that can occur in people with diabetes.

Also rare is fasting hypoglycemia, a condition in which blood sugars are 50 mg/dl or lower after an over-night fast or between meals. Certain medications and medical conditions can cause this problem in children who do not have diabetes.

Demographics

Among children with diabetes, hypoglycemia is much more common in those with type 1 diabetes (also known as insulin-dependent diabetes or juvenile diabetes) than in those with type 2 diabetes (formerly known as adult-onset diabetes).

Causes and symptoms

Hypoglycemia in children and teens with diabetes can be triggered by too much insulin, excessive exercise without proper food intake, certain oral medications, skipping meals, and drinking alcoholic beverages.

Symptoms of hypoglycemia include:

• shakiness
• nervousness
• irritability
• dizziness
• sweating
• confusion
• fatigue
• hunger
• feelings of anxiety

Reactive hypoglycemia can be triggered by enzyme disorders and by gastric bypass surgery. Causes of fasting hypoglycemia in children without diabetes may include insulin-producing tumors, certain hormonal deficiencies, medications (including sulfa drugs and large doses of aspirin), and critical illnesses. Fasting hypoglycemia is more likely to occur in children under the age of 10.

When to call the doctor

Children who are experiencing frequent episodes of hypoglycemia should see their diabetes care doctor as soon as possible as they may require an insulin adjustment, medication change, or another change in their treatment regimen.

If a child or teen with diabetes starts experiencing low blood sugars without any symptoms, he or she may be developing hypoglycemic unawareness and the child's physician should be notified immediately. In hypoglycemic unawareness, the body stops sending its normal warning signs of hypoglycemia, and a child may not realize that blood glucose levels are dangerously low until he or she loses consciousness.

Diagnosis

Episodes of hypoglycemia in children and adolescents with diabetes can be confirmed with a blood test on a home blood glucose monitor. A small needle or lancet is used to prick the finger or an alternate site and a small drop of blood is collected on a test strip that is inserted into the monitor. The monitor then calculates and displays the blood glucose reading on a screen. Although individual blood glucose targets should be determined by a medical professional in light of a child's medical history, the general goal is to keep them as close to normal (i.e., 90 to 130 mg/dl or 5 to 7.2 mmol/L before meals) as possible. Glucose levels that are below 70 mg/dl (3.9 mmol/L) are typically considered hypoglycemic.

In order to diagnose reactive hypoglycemia in those without diabetes, a blood sample must be drawn while a child is experiencing symptoms. If the blood glucose levels are 70 mg/dl or lower and the symptoms subside after food or drink is provided, reactive hypoglycemia is diagnosed.

Treatment

Children with diabetes who exhibit symptoms of hypoglycemia should check their blood glucose levels on a home glucose meter immediately. If levels are 70 mg/dl (3.9 mmol/L) or lower, they should take 15 grams of a fast-acting carbohydrate (e.g., glucose tablets, Life Savers, regular cola), wait 15 minutes, and test their blood sugars again. If levels are still too low, repeating the procedure is necessary until blood glucose is within a safe range.

Giving an unconscious child or teen food or drink by mouth can be potentially dangerous due to the possibility of choking . A glucagon injection should be used on a child that has lost consciousness due to hypoglycemia. Glucagon is a hormone manufactured by the pancreas that triggers the release of blood glucose by the liver. The synthetic version of the hormone is used to rapidly raise blood glucose levels in people with diabetes experiencing a severe low. A glucagon injection kit contains a syringe of sterile water and a vial of powdered glucagon. The water is injected into the glucagon vial and then mixed, and the resulting solution is drawn back into the syringe for injection into any muscular area (e.g., arm, buttock, thigh). Glucagon can cause vomiting , so a child that is given a glucagons injection should be monitored carefully to prevent aspiration.

Episodes of reactive and fasting hypoglycemia in children without diabetes can also be treated with a fast-acting carbohydrate.

Nutritional concerns

For children with diabetes, eating or drinking large quantities of carbohydrates in an attempt to push blood glucose levels back to normal can result in hyperglycemia , or blood sugars that are too high. The 15 grams/15 minutes rule is important to follow to avoid dramatic blood sugar swings.

Eating small, frequent meals and spreading carbohydrate intake throughout the day may help keep blood glucose levels from bouncing too high or too low.

Prognosis

With early detection and immediate and appropriate treatment, children will recover quickly from hypoglycemia.

Prevention

The best way to prevent hypoglycemia is to check blood glucose levels frequently and treat falling blood sugars before they become dangerously low. However, even the most dedicated child or parent may be faced with situations that trigger lows, such as a delay in restaurant service after an insulin injection has been taken or a broken hotel elevator that requires one to climb 20 flights of stairs after a vigorous workout in the pool. Because hypoglycemia can be predictable, children with diabetes and their parents should always have a source of fast-acting carbohydrate on hand for treatment.

A child diagnosed with reactive hypoglycemia can alleviate the problem by consuming small, frequent meals (about every three hours) that are heavy in high-fiber, low-sugar foods. Some physicians may also recommend a high-protein, low-carbohydrate diet.

Parental concerns

Parents of children with diabetes must work with their child's teachers and school administrators to ensure that their child is able to test his or her blood sugars regularly, take insulin as needed, and have access to food or drink to treat hypoglycemia when necessary. Someone at school should also be trained in how to administer a glucagon injection, an emergency treatment for a hypoglycemic episode when a child loses consciousness. Care-givers of children with type 1 diabetes should have access to an emergency glucagon kit and be trained in its use. This should include a responsible adult at the child's school and at any extracurricular activities where parents are not present.

Section 504 of the Rehabilitation Act of 1973 enables parents to develop both a Section 504 plan (which describes a child's medical needs) and an individualized education plan, or IEP (which describes what special accommodations a child requires to address those needs). An IEP should cover issues surrounding hypoglycemia detection and treatment, and should outline how these episodes should be handled.

Because children who are self-conscious about their differences may not comply with their treatment routines as well as they should when their peers are around, parents should work with schools and caregivers to ensure that their child has a clean and private place to test blood glucose levels and take injections.

Teens who drive and have type 1 diabetes should always test their blood glucose levels before getting behind the wheel, and should have a snack before driving if their levels have fallen below the low range of normal (i.e., 90 mg/dl or 5 mmol/L or lower). Keeping the glove compartment stocked with a roll of glucose tablets can help in the case of an unexpected low on the road.

KEY TERMS

Fast-acting carbohydrate —A carbohydrate that causes blood sugar levels to rise quickly rather than slowly and steadily. Also called simple sugars. Examples include glucose tablets, honey, fructose, hard candy, and cake frosting.

Glucagon —A hormone produced in the pancreas that changes glycogen, a carbohydrate stored in muscles and the liver, into glucose. It can be used to relax muscles for a procedure such as duodenography. An injectable form of glucagon is sometimes used to treat insulin shock.

Hypoglycemic unawareness —A condition in which normal warning signals of a blood sugar low, such as shakiness, sweating, or rapid heartbeat, are no longer felt.

Reactive hypoglycemia —A rare condition in which blood sugars drop below normal levels approximately four hours after eating.

Sulfonylurea drug —A medication for type 2 diabetes that causes the pancreas to produce more insulin, and may trigger hypoglycemia in some people.

Because alcohol can also trigger hypoglycemia, adolescents should be informed of the risks of drinking. Parents should let their children know that alcohol is both illegal for minors and potentially dangerous to their health, but they should also ensure that teens know what to do to avoid a dangerous low if they do choose to drink. Food should always accompany alcohol, and anyone who drinks in the evening should consider setting an alarm to test blood sugar levels during the night. Many of the symptoms of hypoglycemia can mimic intoxication, so even those teens who do not drink but do attend parties where alcohol is available should always make sure they are with someone whom they can trust who knows what to do in case of hypoglycemia.

See also Diabetes mellitus.

Resources

BOOKS

Brand-Miller, Jennie Kaye Foster-Powell and Rick Mendosa. What Makes My Blood Sugar Go Up and Down? New York, NY: Marlowe & Company, 2003.

Ford-Martin, Paula. The Everything Diabetes Book. Boston, MA: Adams Media, 2004.

ORGANIZATIONS

American Diabetes Association. 1701 North Beauregard Street, Alexandria, VA 22311. (800) 342–2383. Web site: <www.diabetes.org>.

American Dietetic Association. 216 W. Jackson Blvd., Chicago, IL 60606–6995. (312) 899–0040. Web site: <www.eatright.org>.

Children With Diabetes. Diabetes 123, Inc. 5689 Chancery Place, Hamilton, OH 45011. [email protected]. Web site: <www.childrenwithdiabetes.org>.

Juvenile Diabetes Research Foundation. 120 Wall St., 19th Floor, New York, NY 10005. (800) 533–2873. Web site: <www.jdrf.org>.

National Diabetes Information Clearinghouse. 1 Information Way, Bethesda, MD 20892–3560. (800) 860–8747. [email protected]. Web site: <www.niddk.nih.gov/health/diabetes/ndic.htm>.

Paula Ford-Martin

HYPOGLYCEMIA

DEFINITION

Hypoglycemia (pronounced HI-po-gli-seem-ee-ah) means low blood sugar. The main fuel used by cells to produce energy is a type of sugar called glucose. Glucose is carried to cells in the bloodstream. In that form, glucose is often referred to as "blood sugar." Cells need a minimum amount of glucose to function properly. When there is not enough glucose in the blood to meet those needs, the condition known as hypoglycemia develops.

DESCRIPTION

An important part of the human diet is carbohydrates—sugars and starches. Carbohydrates are changed in the digestive system to glucose. The bloodstream carries glucose to cells. Cells use glucose to produce the energy needed for walking, talking, and just staying alive.

In some cases, people do not get enough glucose in their regular diet. Or they get enough glucose, but their body does not use it properly. In such cases, the person develops hypoglycemia. Hypoglycemia can develop in several ways.

Drug-induced Hypoglycemia

Hypoglycemia occurs frequently among diabetics (see diabetes mellitus entry). Diabetics are people whose bodies cannot use glucose properly. Their bodies either cannot manufacture or cannot use a compound known as insulin. Insulin (pronounced IN-soo-lin) is needed to convert glucose into a form that cells can use.

Diabetics whose bodies don't manufacture insulin control their disorder by taking insulin shots. Diabetics whose bodies don't recognize insulin can adjust their diet to deal with the condition. Missing a meal or taking too much insulin can cause hypoglycemia. This can cause a severe reaction known as "insulin shock."

Idiopathic Or Reactive Hypoglycemia

Idiopathic hypoglycemia occurs most commonly after a person has eaten. The cause for this type of hypoglycemia is not known. It may occur when an organ, such as the liver or pancreas, is not functioning properly. However, the condition is not related to diabetes.

Idiopathic hypoglycemia also occurs among people who have negative reactions to certain foods and drugs. For example, some children have a negative reaction to aspirin that can cause hypoglycemia. Other children have a negative reaction to natural fruit sugar (fructose) that can produce hypoglycemia.

Fasting Hypoglycemia

Strenuous exercise or going without food for long periods of time may also cause hypoglycemia. This form of hypoglycemia is called fasting hypoglycemia.

Hypoglycemia: Words to Know

Diabetes:

A disorder in which the body's cells are unable to use glucose properly in order to make energy.

Glucose:

A simple sugar used by cells to make energy.

Insulin:

A hormone needed by cells to convert glucose to energy.

Metabolism:

A series of chemical reactions by which cells convert glucose to energy.

Other factors can also cause hypoglycemia, including:

• Pregnancy
• A weakened immune system
• A poorly balanced diet that contains too much sugar
• Prolonged use of certain drugs, including antibiotics
• Chronic (ongoing) physical or mental stress
• An irregular heartbeat
• Allergies (see allergies entry)
• Breast cancer (see breast cancer entry)
• Surgery in the upper gastrointestinal (digestive) tract

CAUSES

The carbohydrates we eat are changed into glucose in the digestive system. The glucose passes into the bloodstream and is carried to cells, where it is used to make energy.

Under normal conditions, blood contains just the right amount of glucose. Cells receive all the glucose they need to function properly. But sometimes, blood contains too much or too little glucose. These conditions are called hyperglycemia ("hyper" means "too much") and hypoglycemia ("hypo" means "too little"). Cells either get more glucose than they can use or do not get enough to function normally.

These conditions are caused by two factors. First, a person may eat a diet that provides too much or too little glucose to the body. For example, people who eat a lot of sugar may develop hypoglycemia.

Second, the cells in a person's body may lack the ability to use glucose normally. The person may have inherited the defect from his or her parents. Or something may have happened in the person's life to cause the defect. In either case, the person's blood contains too much or too little glucose. In the latter case, hypoglycemia results.

There is some debate about the nature of idiopathic hypoglycemia. The condition is being diagnosed much less frequently than it was a few decades ago. Some doctors think the condition is caused by other medical problems and is not a disorder in and of itself. Others think that idiopathic hypoglycemia is actually an early stage of diabetes.

SYMPTOMS

Symptoms differ somewhat depending on the type of hypoglycemia that occurs. In the case of drug-induced hypoglycemia, the symptoms may resemble those of extreme shock. They include:

• Cold, pale skin
• Numbness around the mouth
• Anxiety
• Palpitations (irregular heartbeat)
• Emotional outbursts
• Hand tremors (shaking)
• Mental confusion
• Dilated (enlarged) pupils
• Sweating
• Fainting

Idiopathic hypoglycemia is often characterized by milder symptoms, such as:

• Extreme tiredness
• Loss of alertness
• Loss of muscular strength and coordination
• Headache
• Double vision
• Staggering or inability to walk
• A craving for salt or sweets
• Allergies
• Ringing in the ears
• Inflammation of the skin
• Pain in the neck and shoulders
• Memory problems
• Excessive sweating

DIAGNOSIS

Hypoglycemia can be difficult to diagnose. Its symptoms may change over time. Patients seldom have all or even most of the symptoms listed above. Also, the symptoms of hypoglycemia are similar to those seen in other disorders.

The first step in diagnosis, therefore, is to rule out other possible causes for a patient's symptoms. Even then, the patient may have two or more problems at the same time, only one of which is hypoglycemia.

Drug-induced Hypoglycemia

Patients with drug-induced hypoglycemia have already been diagnosed with a blood-sugar problem. They may already be taking insulin to control their disorder. Or they may be aware of the need for following a certain diet. These patients can usually diagnose their own episodes of hypoglycemia. They can carry with them a simple machine known as a glucometer. They can take a small sample of their blood and test it in the glucometer. If their blood glucose level is too low, the patient can raise it by eating a small amount of sugar.

Idiopathic Hypoglycemia

A standard test for idiopathic hypoglycemia is called an extended oral glucose tolerance test. The patient is instructed to fast (not eat any food) overnight. The patient then drinks a solution of glucose in water. His or her blood is then tested every hour for five to six hours. The results of this test indicate the patient's ability to metabolize glucose.

TREATMENT

The fastest treatment for hypoglycemia is to have the patient eat some sugar. A piece of candy or some fruit juice will usually raise blood sugar quickly. Special glucose tablets or injections (shots) of glucose can also be used.

Long-term treatment of hypoglycemia requires changes in a person's diet. The usual recommendation is for a person to eat small but frequent meals throughout the day. They should avoid simple sugars, alcohol, fats, and fruit juice.

Alternative Treatment

Some homeopathic practitioners believe that hypoglycemia may be caused by a number of factors. They recommend a variety of treatments that may include acupuncture and herbal remedies. One suggested drink is made by boiling gentian (an herb) in water. Some practitioners also recommend adding chromium to the diet. Chromium is thought by some practitioners to help stabilize blood-sugar levels. Chromium is found in whole-grain breads and cereals, cheeses, molasses, lean meats, and brewer's yeast.

PROGNOSIS

All forms of hypoglycemia can usually be controlled by following a well-planned diet. In addition, diabetics can often control drug-induced episodes of hypoglycemia by monitoring their blood glucose levels.

PREVENTION

Methods of prevention vary depending on the cause of the hypoglycemia.

Drug-induced Hypoglycemia

The first step in preventing drug-induced hypoglycemia is to maintain a proper diet. Diabetics may also find it necessary to monitor their blood-sugar levels on a regular basis. Low blood-sugar levels indicate that a person should immediately eat candy or some other sweet snack. Insulin pumps are also effective in maintaining the proper level of blood sugar. These pumps can be implanted under the skin and programmed to continuously release the correct amount of insulin.

Idiopathic Hypoglycemia

Idiopathic hypoglycemia can usually be controlled by learning and following certain dietary rules. These rules include the following:

• Avoid overeating.
• Never skip breakfast.
• Include protein in all meals and snacks.
• Limit intake of fats, refined sugar, and processed foods.
• Become familiar with the sugar content in different kinds of vegetables and grain products.
• Keep a food diary that can be used to predict which foods produce the symptoms of hypoglycemia.
• Eat a regular but limited amount of fresh fruits.
• Follow a diet that is high in fiber.

FOR MORE INFORMATION

Books

Budd, Martin. Low Blood Sugar: Coping With Low Blood Sugar. London: Thorsons Publications, 1998.

Eades, Michael R., and Mary Dan. Protein Power. New York: Bantam Books, 1995.

Krimmel, Patricia, and Edward Krimmel. The Low Blood Sugar Handbook. Bryn Mawr, PA: Franklin Publishers, 1992.

Ruggiero, Roberta. The Do's and Dont's of Low Blood Sugar. Hollywood, FL: Frederick Fell Publishers, 1988.

Organizations

Hypoglycemia Association, Inc. 1808 New Hampshire Ave., P.O. Box 165, Ashton, MD 20861–0165.

National Hypoglycemia Association, Inc. PO Box 120, Ridgewood, NJ 07451. (201) 670–1189.

Hypoglycemia

Melinda’s Story

What Is Hypoglycemia?

How Is Hypoglycemia Diagnosed?

Hypoglycemia (hy-po-gly-SEE-mee-a) is a condition that occurs when the amount of sugar in the blood gets too low.

KEYWORDS

for searching the Internet and other reference sources

Carbohydrate metabolism

Glycogen

Insulinoma

Melinda’s Story

Melinda was at the mall with friends, when she started to feel weak and uncoordinated. She developed a pounding headache, began to shake and sweat, and could not see very well. Because Melinda had diabetes, her doctor had warned her about these symptoms, and she knew they meant that her blood sugar had gotten too low. She carried candy in her backpack at all times for just such an occasion. Melinda told her friends that she should not have skipped lunch because a sensible diet and regular meals help prevent hypoglycemia in people being treated for diabetes. Melinda told them that hypoglycemia can cause coma* if not treated. After eating her candy bar, Melinda felt better within minutes.

* coma

(KO-ma) is an unconscious state, like a very deep sleep. A person in a coma cannot be woken up, and cannot move, see, speak, or hear.

What Is Hypoglycemia?

Hypoglycemia means low (“hypo”) blood sugar (“glycemia”). Hypoglycemia is not a disease; it a symptom of a problem the body has with regulating blood sugar. Its opposite, hyperglycemia (hy-per-gly-SEE-mee-a), means too much sugar in the blood, which is one of the features of diabetes.

Many people being treated for diabetes experience hypoglycemia. Diabetes is a disorder characterized by high levels of sugar in the blood due to the body’s inability to make enough of the hormone insulin or to respond to insulin normally. People being treated with insulin for diabetes sometimes take too much insulin or may not eat enough, as happened to Melinda at the mall. In fact, 90 percent of people with insulin-dependent diabetes have occasional periods of hypoglycemia.

Severe hypoglycemia sometimes is called “insulin shock,” because symptoms occur if people take too much insulin or if their body makes too much insulin. It is rare for people without diabetes to have hypoglycemia. The two main categories of hypoglycemia are reactive hypoglycemia and fasting hypoglycemia.

Reactive hypoglycemia

Reactive hypoglycemia occurs after eating, especially after a meal containing lots of sugary or starchy foods. The sugar from the meal causes the body to make a great deal of insulin rapidly in order to keep blood sugar from rising too high. But the body makes so much insulin that the blood sugar level drops too low instead.

Fasting hypoglycemia

Fasting hypoglycemia occurs several hours after the person’s last meal. It can happen to people with diabetes or as a result of several other conditions, including anorexia nervosa*, starvation, a tumor* of the pancreas (the gland that secretes insulin), cancer, and certain hormonal and metabolic diseases.

* anorexia nervosa

(an-o-REK-se-a ner-VO-sa) is an emotional disorder characterized by dread of gaining weight, leading to self-starvation and dangerous loss of weight and malnutrition.

* tumor

(TOO-mor) usually refers to an abnormal growth of body tissue that has no known cause or physiologic purpose.

How Is Hypoglycemia Diagnosed?

To find out if a person has hypoglycemia, doctors ask about symptoms and whether they go away when the person eats sugar. The doctor also will examine the patient and take a medical history to look for the specific features of disorders known to be associated with hypoglycemia. Blood tests performed when the person is having symptoms of hypoglycemia can confirm low levels of sugar in the blood, if present, and can measure the levels of insulin and other hormones and substances involved in the control of blood sugar.

See also

Cancer

Diabetes

Eating Disorders

Pancreatic Cancer