Diabetes Health Center

Doctors diagnose hypoglycemia when a person has these three things:

• Symptoms of low blood sugar.
• A blood glucose laboratory test with low results. This is different from a test done with a glucose meter.
• Relief of symptoms when the blood sugar is raised.

Medical history

Your doctor will ask questions about:

• What symptoms you typically have-how long they last, when they occur, how often they occur, and what happens to your symptoms when you eat something.
• Past medical treatments, current medical conditions, and whether you are taking medicines (bring all medicines, both prescription and nonprescription, to your appointment for review) or receiving other treatment.
• Diet and nutrition, such as what and when you eat, and whether you have had recent changes in your eating or bowel habits.
• Whether you have gained or lost weight recently.

Because an episode of hypoglycemia can impair mental functioning, your doctor may also want to talk to friends or relatives who have seen your symptoms.

Your doctor will assess your medical history to see if any of the following could be causing your hypoglycemia:

• Illnesses and other health conditions. Hypoglycemia may occur when other diseases and disorders affect the body's sugar metabolism. These can include disorders of the pancreas and endocrine system; diseases of the liver, adrenal glands (such as Addison's disease), or kidneys; heart failure, which can impair liver function; and sepsis. In very rare cases, nonpancreatic tumors cause hypoglycemia.
• Medicines. Some medicines used to treat conditions other than diabetes can cause hypoglycemia or hide its symptoms.
• Too much insulin. Tumors in the pancreas (insulinomas), certain disorders of the pancreas, or some autoimmune diseases can cause too much insulin to be produced. These conditions are rare.
• Alcohol. In some people, drinking alcohol can cause a drop in blood sugar levels. Hypoglycemia has been linked to chronic alcoholism and binge drinking. Hypoglycemia linked to binge drinking can be particularly severe if a person has not eaten within about 6 hours, because fasting can impair the liver's ability to make new glucose. The person may fall into a coma, which can be fatal.
• Alimentary hypoglycemia. Hypoglycemia within 1 to 2 hours after a meal sometimes occurs when stomach contents empty into the intestines too rapidly. This causes the rapid absorption of glucose into the blood and an overproduction of insulin (hyperinsulinism) in response. This problem may occur after surgery for peptic ulcers, obesity, or other stomach problems.
• Other causes. Hypoglycemia also may occur, though rarely, under certain conditions in early pregnancy or with prolonged fasting or missed meals, severe malnutrition, significant weight loss, or prolonged strenuous exercise, such as running a marathon. It may occur in premature or full-term newborns with a low birth weight and in newborns whose mothers have been treated for type 1 diabetes or gestational diabetes.
• Inborn metabolic problems. In rare cases, hypoglycemia may be caused by inherited enzyme or hormone deficiencies, especially those that affect the metabolism of sugars and other carbohydrates. These conditions are often discovered in infancy or childhood.
• Factitious hypoglycemia. Hypoglycemia can be caused intentionally by the inappropriate use of insulin and sulfonylurea medicines. This is most often seen in health professionals and people who have diabetes or their relatives. The reasons for self-induced hypoglycemia vary and may be associated with psychiatric problems or a need for attention, similar to Munchausen syndrome.

Physical exam