Fasting hypoglycemia is a condition in which the body fails to produce enough sugar in the blood after a period of time without food. This occurs most often in people with some form of diabetes because the pancreas is unable to produce and regulate adequate levels of insulin. Normally healthy people rarely experience fasting hypoglycemia unless it is the result of an underlying cause, though once in a while it is possible.
Fasting hypoglycemia most often occurs in the morning or late afternoons when meals are skipped. A normally healthy individual might not experience the symptoms of fasting hypoglycemia even after going eight to ten hours without food, however, if there is an underlying cause, symptoms may appear. Symptoms include dizziness, shaking, sweating, faintness or passing out. These symptoms could easily appear in a healthy individual who has skipped meals or not eaten in more than eight to ten hours, but they would be mild. If these symptoms occur after only five to six hours without food or are severe enough to cause fainting or seizures, it could be an indication of something serious.
Fasting hypoglycemia is similar to reactive hypoglycemia, which occurs shortly after meals and diabetic-related hypoglycemia. In diabetic individuals, fasting hypoglycemia can easily occur if a meal is missed. In non-diabetics, hypoglycemia may indicate a pancreatic tumor, liver disease, thyroid problem, or a host of other conditions, however the symptoms of low-blood sugar are likely not the first or only symptom.
People who experience fasting hypoglycemia may also be experiencing a side effect of certain medications. If you are taking medication and experience the symptoms of hypoglycemia upon waking or five or more hours after a meal, talk to your doctor or pharmacist to determine if this is normal. If you have hypoglycemic symptoms with or without other indicators, you should schedule an appointment with your health care provider. He or she may want to conduct blood tests and other diagnostic tests to determine if there is a chronic problem developing or if an underlying condition is causing the symptoms.
Rarely, otherwise healthy individuals may experience mild hypoglycemia after prolonged periods without food. These symptoms can also manifest after excessive alcohol consumption with very little food intake. Prolonged fasting or excessive strenuous exercise without food can also cause fasting hypoglycemia in otherwise healthy people. Repeated incidents of fasting hypoglycemia are not normal in healthy individuals and should be discussed with a doctor.