Fasting Hypoglycemia

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.

Conditions Occurring in Infancy and Childhood

Children rarely develop hypoglycemia. If they do, causes may include

Brief intolerance to fasting, often in conjunction with an illness that disturbs regular eating patterns. Children usually outgrow this tendency by age 10.
Hyperinsulinism, which is the excessive production of insulin. This condition can result in transient neonatal hypoglycemia, which is common in infants of mothers with diabetes. Persistent hyperinsulinism in infants or children is a complex disorder that requires prompt evaluation and treatment by a specialist.
Enzyme deficiencies that affect carbohydrate metabolism. These deficiencies can interfere with the body's ability to process natural sugars, such as fructose and galactose, glycogen, or other metabolites.
Hormonal deficiencies such as lack of pituitary or adrenal hormones.

Hope Through Research

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) was established by Congress in 1950 as one of the National Institutes of Health under the U.S. Department of Health and Human Services. The NIDDK conducts and supports research in diabetes, glucose metabolism, and related conditions. Researchers supported by NIDDK are investigating topics such as

What are the causes of hypoglycemia?
Can islet cell transplantation eliminate hypoglycemia?
Can laparoscopy (a surgical procedure) be used to find and remove insulinomas (insulin-producing tumors)?
Do new frequent-glucose-monitoring devices help prevent hypoglycemia?
Why do repeated episodes of hypoglycemia lead to loss of awareness of hypoglycemia symptoms?

A complete listing of clinical research studies can be found at http://ClinicalTrials.gov on the Internet.

Points to Remember

Diabetes-Related Hypoglycemia

If you think your blood glucose is low, check it and treat the problem right away.
To treat hypoglycemia, have a serving of a quick-fix food, wait 15 minutes, and check your blood glucose. Repeat the treatment until your blood glucose is above 70.
Keep quick-fix foods in the car, at work—anywhere you spend time.
Be careful when you are driving. Check your blood glucose frequently and snack as needed to keep your level above 70 mg/dL.

Hypoglycemia Unrelated to Diabetes

In reactive hypoglycemia, symptoms occur within 4 hours of eating. People with this condition are usually advised to follow a healthy eating plan recommended by a registered dietitian.
Fasting hypoglycemia can be caused by certain medications, critical illnesses, hereditary enzyme or hormonal deficiencies, and some kinds of tumors. Treatment targets the underlying problem.