Hypoglycemia, or low blood sugar, has several causes. Symptoms of hypoglycemia include tremors, cold sweats, confusion, dizziness, lightheadedness, blurred vision, pounding heart and feelings of hunger and can lead to coma, seizures or, in extreme cases, death. Symptoms of hypoglycemia, which are caused by release of adrenaline as blood sugar drops and by a lack of glucose reaching the brain, generally don't occur until blood glucose levels fall below 60 milligrams per deciliter, according to the Merck Manual.
Excess Diabetic Medication
People with diabetes either don't make enough insulin or have an increased need for insulin. Insulin injections provide insulin when the body doesn't make enough, while oral medications for diabetes increase the body's ability to create insulin or decrease the ability to manufacture glucose. Taking more insulin or oral anti-diabetic medication than needed causes blood glucose to drop too low. Taking insulin and then exercising or not eating enough are also potential causes of hypoglycemia.
Reactive Hypoglycemia
Some people who don't have diabetes develop reactive or postprandial hypoglycemia, hypoglycemia that develops after eating a meal containing a large number of carbohydrates. More insulin than is needed is released from the pancreas and blood sugar drops. Reactive hypoglycemia more commonly occurs in people who have had gastric bypass surgery, according to the Mayo Clinic.
Pancreatic Tumors
Pancreatic tumors of various types sometimes produce an excess amount of insulin and lead to hypoglycemia that may occur more frequently in the morning. Hypoglycemic episodes may occur infrequently at first and then become more frequent over time, according to Merck. Other types of pancreatic tumors may use up more glucose, resulting in hypoglycemia. Tumors in the beta cells of the pancreas occur more frequently in people who have undergone gastric bypass, according to the Mayo Clinic.
Other Substances
Some medications besides insulin and other diabetic drugs can lead to hypoglycemia. Quinine, taken to prevent or treat leg cramps and pentamidine, a drug used to treat pneumonia that develops mostly in AIDS patients, may cause hypoglycemia in some people, according to the Merck Manual. Alcohol ingestion, especially if heavy and taken without food, can lead to hypoglycemia because the alcohol blocks the release of glucose from the liver.
Illnesses
Some diseases, such as severe liver or kidney disease, Addison's disease, heart failure, shock or cancer can cause hypoglycemia. Starvation from anorexia nervosa, an eating disorder, can also lead to hypoglycemia.
