Hypoglycemia

Answer 1

Definition

Hypoglycemia is a condition that occurs when your blood sugar (glucose) is too low.

Blood sugar below 70 mg/dL is considered low. Blood sugars at this level can harm you.

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. If you have diabetes and are taking any of the following diabetes medications, you have a risk for low blood sugar:

• Chlorpropamide (Diabinese), tolazamide (Tolinase), acetohexamide (Dymelor), glipizide (Glucotrol), or tolbutamide (Orinase)
• Glyburide (Micronase), glimepiride (Amaryl), repaglinide (Prandin), nateglinide (Starlix), and mitiglinide) -- the risk with these drugs is lower, but still possible
• Insulin

If you have diabetes, low blood sugars may occur 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
• Insulinoma - a tumor in the pancreas that produces too much insulin
• Liver disease

Symptoms

Symptoms you may have when your blood sugar gets too low include:

• Cold sweats
• Convulsions
• Double visionor blurry vision
• Fast or pounding heartbeat
• General discomfort, uneasiness, or ill feeling (malaise)
• Headache
• Hunger
• Irritability (possible aggression)
• Nervousness
• Shaking or trembling
• Sleeping difficulty
• Tingling or numbness of the skin
• Tiredness or weakness
• Unclear thinking

Sometimes your blood sugar may be too low, even if you do not have symptoms. If your blood sugar gets too low, you may:

• Faint
• Have a seizure
• Go into a coma

Other symptoms that may occur with this disease:

• Decreased alertness
• Different size pupils
• Dizziness
• Hallucinations
• Memory loss
• Muscle pain
• Paleness

Signs and tests

Home monitoring of blood sugar will show readings lower than 70 mg/dL.

Serum glucosetest will be low.

Treatment

Treatment depends on the cause.

If you have diabetes, check your blood sugar level whenever you have symptoms of low blood sugar. If your blood sugar is low (70 mg/dL), you need to treat yourself right away.

Eat something that has about 15 grams of carbohydrates. Examples are:

• 3 glucose tablets
• A 1/2 cup (4 ounces) fruit juice or regular, non-Diet Soda
• 5 or 6 hard candies
• 1 tablespoon sugar, plain or dissolved in water
• 1 tablespoon honey or syrup

Wait about 15 minutes before eating any more. Be careful not to over-treat by eating too much. This can cause high blood sugar and weight gain.

Persons with severe hypoglycemia are treated with glucose injections or the hormone glucagon. Immediate treatment is needed to prevent serious complications or death.

Preventing low blood sugar is better than having to treat it. When you exercise, check your blood sugar levels. Make sure you have snacks with you if you take insulin or other medicines that lower your blood sugar.

Ask your doctor or nurse if you need a bedtime snack to prevent low blood sugar overnight. Protein snacks may be best. Do not drink alcohol without eating food. If you do drink, have only one or two drinks at the most.

Your doctor may tell you to change your diet so that you get more even amounts of glucose into your body throughout the day. 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.

American Diabetes Association. Standards of medical care in diabetes--2010. Diabetes Care. 2010;33 Supl 1:S11-S61.

Answer 2

Definition

Hypoglycemia is a condition that occurs when your blood sugar (glucose) is too low.

Blood sugar below 70 mg/dL is considered low. Blood sugar at or below this level can harm you.

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.

The most common causes of low blood sugar in people with diabetes are:

• Taking your insulin or diabetes medicine at the wrong time
• Taking too much insulin or diabetes medicine by mistake
• Not eating enough during meals or snacks after you have taken insulin or diabetes medicine
• Skipping meals
• Waiting to eat your meals
• Exercising more or at a different time than usual
• Drinking alcohol

If you have diabetes and are taking any of the following diabetes medications, you have a risk for low blood sugar:

• Chlorpropamide (Diabinese), tolazamide (Tolinase), acetohexamide (Dymelor), glipizide (Glucotrol), or tolbutamide (Orinase)
• Glyburide (Micronase), glimepiride (Amaryl), repaglinide (Prandin), nateglinide (Starlix), and mitiglinide) -- the risk with these drugs is lower, but still possible
• Insulin

A newborn's blood sugar can become low. Babies who are born to mothers with diabetes may have severe drops in blood sugar.

Hypoglycemia in people who do not have diabetes may be caused by:

• Drinking alcohol
• Insulinoma - a tumor in the pancreas that produces too much insulin
• Liver disease

Symptoms

Symptoms you may have when your blood sugar gets too low include:

• Double visionor blurry vision
• Fast or pounding heartbeat
• Feeling cranky or acting aggressive
• Feeling nervous
• Headache
• Hunger
• Shaking or trembling
• Sleeping trouble
• Sweating
• Tingling or numbness of the skin
• Tiredness or weakness
• Unclear thinking

Sometimes your blood sugar may be too low, even if you do not have symptoms. If your blood sugar gets too low, you may:

• Faint
• Have a seizure
• Go into a coma

Signs and tests

Home monitoring of blood sugar will show readings lower than 70 mg/dL.

Serum glucosetest will be low.

Treatment

Treatment depends on the cause.

If you have diabetes, check your blood sugar level whenever you have symptoms of low blood sugar. If your blood sugar is low (70 mg/dL), you need to treat yourself right away.

Eat something that has about 15 grams of carbohydrates. Examples are:

• 3 glucose tablets
• A 1/2 cup (4 ounces) of fruit juice or regular, non-diet soda
• 5 or 6 hard candies
• 1 tablespoon sugar, plain or dissolved in water
• 1 tablespoon honey or syrup

Wait about 15 minutes before eating anything else. Be careful not to over-treat by eating too much. This can cause high blood sugar and weight gain.

Check your blood sugar again.

• If you don't feel better in 15 minutes and your blood sugar is still low (less than 70 mg/dL), eat something that has 15 grams of carbohydrates again.
• You may need to eat a snack that has carbohydrates and protein if your blood sugar is in a safer range (over 70 mg/dL) and your next meal is more than an hour away.

If these steps for raising your blood sugar do not work, call your doctor right away.

Persons with severe hypoglycemia are treated with glucose injections or the hormone glucagon. Immediate treatment is needed to prevent serious complications or death.

If hypoglycemia is caused by an insulinoma (insulin-releasing 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 cause seizures and permanent damage to the nervous system if not treated. Severe hypoglycemia in which you become unconscious is also called insulin shock.

Learn to recognize the early warning signs of hypoglycemia and treat yourself quickly.

Calling your health care provider

If signs of low blood sugar do not improve after you have eaten a snack that contains sugar:

• GET A RIDE to the emergency room, or
• Call a local emergency number (such as 911)

DO NOT drive when your blood sugar is low.

Get medical help right away for a person with diabetes or low blood sugar who:

• Becomes less alert
• Cannot be woken up

Prevention

If you have diabetes, follow your doctor's advice about diet, medicine, and exercise.

Preventing low blood sugar is better than having to treat it. When you exercise, check your blood sugar levels. Make sure you have snacks with you if you take insulin or other medicines that lower your blood sugar.

Ask your doctor or nurse if you need to eat a bedtime snack to prevent low blood sugar overnight. Protein snacks may be best.

Do not drink alcohol without eating food. If you do drink, have only one or two drinks at the most.

Your doctor may tell you to change your diet so that you get even amounts of sugar into your body throughout the day. You may be told to eat small, frequent meals that contain complex carbohydrates, fiber, and fat, and to avoid simple sugars, alcohol, and fruit juice.

Eat meals at regular times. Eat extra food when you exercise more.

If you have a history of hypoglycemia, keep a snack or drink containing sugar with you at all times. Eat the snack as soon as symptoms appear.

References

American Diabetes Association. Standards of medical care in diabetes--2011. Diabetes Care. 2011;34 Supl 1:S11-S61.

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

Review Date: 06/28/2011

Ari S. Eckman, MD, Division of Endocrinology, Diabetes and Metabolism, Trinitas Regional Medical Center, Elizabeth, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.