Hypoglycemia in People Who Do Not Have Diabetes: Fasting Hypoglycemia

Diagnosis
Fasting hypoglycemia is diagnosed from a blood sample that shows a blood glucose level of less than 50 mg/dL after an overnight fast, between meals, or after exercise.

Causes and Treatment
Causes include certain medications, alcohol, critical illnesses, hormonal deficiencies, some kinds of tumors, and certain conditions occurring in infancy and childhood.

Medications
Medications, including some used to treat diabetes, are the most common cause of hypoglycemia. Other medications that can cause hypoglycemia include

• salicylates, including aspirin, when taken in large doses
• sulfa medicines, which are used to treat infections
• pentamidine, which treats a very serious kind of pneumonia
• quinine, which is used to treat malaria

If using any of these medications causes your blood glucose to drop, your doctor may advise you to stop using the drug or change the dosage.

Alcohol
Drinking, especially binge drinking, can cause hypoglycemia because your body's breakdown of alcohol interferes with your liver's efforts to raise blood glucose. Hypoglycemia caused by excessive drinking can be very serious and even fatal.

Critical Illnesses
Some illnesses that affect the liver, heart, or kidneys can cause hypoglycemia. Sepsis (overwhelming infection) and starvation are other causes of hypoglycemia. In these cases, treatment targets the underlying cause.

Hormonal Deficiencies
Hormonal deficiencies may cause hypoglycemia in very young children, but usually not in adults. Shortages of cortisol, growth hormone, glucagon, or epinephrine can lead to fasting hypoglycemia. Laboratory tests for hormone levels will determine a diagnosis and treatment. Hormone replacement therapy may be advised.

Tumors
Insulinomas, insulin-producing tumors, can cause hypoglycemia by raising your insulin levels too high in relation to your blood glucose level. These tumors are very rare and do not normally spread to other parts of the body. Laboratory tests can pinpoint the exact cause. Treatment involves both short-term steps to correct the hypoglycemia and medical or surgical measures to remove the tumor.

source: http://diabetes.niddk.nih.gov/dm/pubs/hypoglycemia/index.htm