Hypoglycemia: Low blood sugar (glucose). When symptoms of hypoglycemia occur together with a documented blood glucose under 45 mg/dl, and the symptoms promptly resolve with the administration of glucose, the diagnosis of hypoglycemia can be made with some certainty. Hypoglycemia is only significant when it is associated with symptoms.
The symptoms may include anxiety, sweating, tremor, palpitations, nausea, and pallor. Hypoglycemia also starves the brain of glucose energy, which is essential for proper brain function. Lack of glucose energy to the brain can cause symptoms ranging from headache, mild confusion, and abnormal behavior, to loss of consciousness, seizure, and coma. Severe hypoglycemia can cause death.
The causes of hypoglycemia include drugs (such as insulin), liver disease, surgical absence of the stomach, tumors that release excess amounts of insulin, and pre-diabetes. In some patients, symptoms of hypoglycemia occur during fasting (fasting hypoglycemia). In others, symptoms of hypoglycemia occur after meals (reactive hypoglycemia).
Immediate treatment of severe hypoglycemia consists of administering large amounts of glucose, and repeating this treatment at intervals if the symptoms persist. Treatment must also be directed at the underlying cause. Patients with diabetes mellitus who develop low blood glucose from their medicines require medication adjustments. Treatment of reactive hypoglycemia consists of dietary measures, including fewer concentrated sweets and the ingestion of multiple small meals throughout the day.