• 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