Nearly one out of five people with type 1 diabetes may experience "hypoglycemia unawareness," an inability to recognize the symptoms of low blood glucose.

Normally, when blood glucose levels get too low, the body releases epinephrine as a defense mechanism. Epinephrine causes symptoms such as palpitations, sweating and anxiety that serve to warn the person that blood glucose is dropping so that he/she can take action to reverse the condition.

The more severe and frequent the hypoglycemic episodes are, the more the body "turns off" its ability to recognize and respond to future episodes. When this happens falling blood glucose levels do not trigger the secretion of epinephrine, and no symptoms occur to warn the patient of a problem. Episodes of hypoglycemia unawareness can result in prolonged hypoglycemia, which can lead to brain injury, seizure or loss of consciousness. Hypoglycemic unawareness is a particular problem for people trying to achieve tight control.

Some experts recommend that this abnormality can be reversed by keeping the blood glucose levels somewhat elevated for a few days and avoiding hypoglycemia.

Related information More about hypoglycemia

Sources:

• NIH. Understanding hypoglycemia unawareness in patients with diabetes. RFP, July 27, 2001.
• Hypoglycemia unawareness. DiabetesNet.