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Hypoglycemia
Definition
Hypoglycemia is a condition that occurs when your blood sugar (glucose) is too low.
Alternative Names
Insulin shock; Low blood sugar
Causes, incidence, and risk factors
Hypoglycemia occurs when:
- Your body's sugar (glucose) is used up too quickly
- Glucose is released into the bloodstream too slowly
- Too much insulin is released into the bloodstream
Insulin is a hormone that reduces blood sugar. It is produced by the pancreas in response to increased glucose levels in the blood.
Hypoglycemia is relatively common in persons with diabetes. It occurs when:
- You take too much insulin or diabetes medicine
- You don't eat enough food
- You suddenly increase your exercise without increasing the amount of food you eat
Relative hypoglycemia is a fairly common condition in which a newborn's blood sugar is low. Babies born to mothers with diabetes may have severe hypoglycemia.
Idiopathic hypoglycemia is hypoglycemia that occurs without a known cause. People with this type of hypoglycemia do not have diabetes.
Hypoglycemia may also be caused by:
- Ingestion of alcohol
- Insulin-secreting tumor of the pancreas
- Liver disease
Symptoms
- Cold sweats
- Confusion
- Convulsions
- Coma
- Double vision or blurry vision
- Fatigue
- General discomfort, uneasiness, or ill feeling (malaise)
- Headache
- Hunger
- Irritability (possible aggression)
- Nervousness
- Rapid heart rate
- Trembling
Other symptoms that may be associated with this disease:
- Decreased alertness
- Different size pupils
- Dizziness
- Excessive sweating
- Fainting
- Hallucinations
- Memory loss
- Muscle pain
- Paleness
- Pounding heartbeat (heartbeat sensations)
- Sleeping difficulty
Signs and tests
Home monitoring of blood sugar will show readings lower than 50 mg/dL.
Serum glucose test will be low.
Treatment
Treatment depends on the cause.
In people with diabetes who take medication that lowers blood sugar, a snack or drink containing sugar will raise the blood glucose level. Try to drink no more than 4 ounces of juice or sugar soda. You should see an immediate improvement in symptoms. If you do not, check blood sugar and repeat after 15 minutes. Overtreatment of low blood sugar can cause problems with high blood sugar in people with diabetes.
Persons with severe hypoglycemia are treated with glucose injections or the hormone glucagon. Immediate treatment is needed to prevent serious complications or death.
Your doctor may tell you to change your diet so that you get more even amounts of glucose into your body throughout the day. This may prevent further episodes of low blood sugar. You may be told to eat small, frequent meals with complex carbohydrates, fiber, and fat and to avoid simple sugars, alcohol, and fruit juice.
You should also eat meals at regular intervals, and balance extra exercise with extra food.
If hypoglycemia is caused by an insulinoma (insulin-secreting tumor), surgery to remove the tumor is the best treatment.
Complications
Untreated, hypoglycemia from too much insulin can lead to loss of consciousness and coma. Severe hypoglycemia is a medical emergency that may result in seizures and permanent damage to the nervous system if not treated. Severe hypoglycemia that results in unconsciousness is also called insulin shock.
Learn to recognize the early warning signs of hypoglycemia and treat yourself quickly and appropriately.
Calling your health care provider
Go to the emergency room immediately or call a local emergency number (such as 911) if early signs of hypoglycemia do not improve after you've eaten a snack containing sugar.
Get immediate medical help if a person with diabetes or a history of hypoglycemia loses alertness or if you can't wake them up.
Prevention
If you have diabetes, make sure you follow your doctor's advice regarding diet, medications, and exercise.
If you have a history of hypoglycemia, you should keep a snack or drink containing sugar available at all times to take as soon as symptoms appear. If symptoms do not improve in 15 minutes, eat more food. A glucagon kit is available for those who have episodes of hypoglycemia that don't respond well to other types of treatment.
References
Cryer PE, Davis SN, Shamoon H. Hypoglycemia in diabetes. Diabetes Care. 2003; 26(6): 1902-1912.
Cryer PE. Glucose Homeostasis and Hypoglycemia. In: Kronenberg HM, Melmed S, Polonsky KS, Larsen PR. Kronenberg: Williams Textbook of Endocrinology. 11th ed. Philadelphia, Pa:Saunders Elsevier; 2008:chap 33.
Reviewed By: Reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. Also reviewed by Deborah Wexler, MD, Assistant Professor of Medicine, Harvard Medical School, Endocrinologist, Massachusetts General Hospital.
