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

Hypoglycemia, or abnormally low blood sugar, is caused by the impaired response (or failure) of the liver to release glucose as blood sugar levels decrease. The imbalance in the rate of glucose released from the liver and its use by other body tissues can result in the following hypoglycemic symptoms: hunger, nervousness, dizziness, confusion, sleepiness, difficulty speaking, feeling anxious or weak, irritability, sweating, loss of consciousness, and increased blood pressure . In diabetic individuals, too much insulin , limited or delayed food intake, a sudden increase in exercise, and excessive alcohol ingestion cause fasting hypoglycemia. Reactive hypoglycemia, however, occurs about four hours after a meal. The cause is unknown, but experts speculate that deficiencies in the release of glucagon (hormone released by the pancreas to increase blood glucose levels) and sensitivity to epinephrine (hormone released by the adrenal glands) contribute to hypoglycemia.

Normal blood sugar levels range from 70 to 110 mg/dl (milligrams per deciliter) upon waking and 70 to 140 mg/dl following meals. For those with diabetes , blood glucose levels before meals should be between 90 mg/dl and 130 mg/dl. One to two hours after a meal, blood glucose values should be less than 180 mg/dl. A blood sugar level of 70 mg/dl or less is defined as hypoglycemia. Severe hypoglycemia occurs when values are less than 40 mg/dl. Diagnosis of hypoglycemia requires fasting blood glucose values of less than 50mg/dl or of blood glucose values less than 70 mg/dl after ingesting food or drink. Treatment for hypoglycemia involves administering sugar in the form of glucose tablets, fruit juice, regular soft drinks, milk, hard candy, honey, or sugar. Hypoglycemia is prevented with regular meals and limiting alcohol and caffeine intake.

see also Diabetes Mellitus; Insulin.

Julie Lager

Bibliography

Cryer, Philip E.; Fisher, Joseph N.; and Shamoon, Harry (1994). "Hypoglycemia." Diabetes Care 17(7):734–755.

Internet Resources

American Diabetes Association. "Tight Diabetes Control." Available from <http://www.diabetes.org>

National Institute of Diabetes and Digestive and Kidney Diseases. "Hypoglycemia." Available from <http://www.niddk.nih.gov>

National Library of Medicine. "Diabetes." Available from <http://www.medlineplus.gov/>

hypoglycaemia An abnormally low concentration of glucose in the blood. With regular meals, and despite an overnight fast, the level does not normally drop at any time below its range of 3.5–5.5 mmol/litre. Healthy people become hypoglycaemic only after a more prolonged fast, or heavy exercise without adequate intake. Severe hypoglycaemia can occur in people with diabetes whose insulin dosage has been excessive relative to food intake. Because the brain depends exclusively on glucose for its metabolism, they may lose consciousness in hypoglycaemic coma, but wake up rapidly if glucose is infused into a vein.

Stuart Judge

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

hypoglycaemia (hy-poh-gly-see-miă) n. a deficiency of glucose in the bloodstream, causing muscular weakness and incoordination, mental confusion, and sweating. If severe it may lead to hypoglycaemic coma. Hypoglycaemia most commonly occurs in diabetes mellitus. It is treated by administration of glucose. reactive h. hypoglycaemia occurring after a meal, induced by excessive levels of insulin release from the pancreas.
—hypoglycaemic (hy-poh-gly-see-mik) adj.

hy·po·gly·ce·mi·a / ˌhīpōglīˈsēmēə/ (Brit. hy·po·gly·cae·mi·a) • n. Med. deficiency of glucose in the bloodstream. DERIVATIVES: hy·po·gly·ce·mic / -ˈsēmik/ adj.

hypoglycaemia Abnormally low level of sugar in the blood. It may result from fasting, excess insulin in the blood, or various metabolic and glandular diseases, notably diabetes. Symptoms include dizziness, headache, sweating, and mental confusion. See also hyperglycaemia

hypoglycaemia Below-normal levels of glucose in the blood plasma, causing weakness, dizziness, and sweating. Compare hyperglycaemia.

hypoglycaemia Abnormally low concentration of plasma glucose; may result in loss of consciousness, hypoglycaemic coma.

hypoglycemia see diabetes .

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