What Is It?
Hypoglycemia is an abnormally low level of blood sugar (blood glucose). Because the brain depends on blood sugar as its primary source of energy, hypoglycemia interferes with the brain's ability to function properly. This can cause dizziness, headache, blurred vision, difficulty concentrating and other neurological symptoms. Hypoglycemia also triggers the release of body hormones, such as epinephrine and norepinephrine. Your brain relies on these hormones to raise blood sugar levels. The release of these hormones causes additional symptoms of tremor, sweating, rapid heartbeat, anxiety and hunger.
Hypoglycemia is most common in people with diabetes. For a person with diabetes, hypoglycemia occurs because of too high a dose of diabetic medication, especially insulin, or a change in diet or exercise. Insulin and exercise both lower blood sugar and food raises it. Hypoglycemia is common in people who are taking insulin or oral medications that lower blood glucose, especially drugs in the sulfonylurea group (Glyburide and others).