Hypoglycemia is an abnormally low level of glucose (sugar) in the blood. The brain requires sugar for normal function, and unlike many other organs, the brain has a very limited ability to store glucose. This means that the brain is the organ predominantly affected when blood glucose gets too low. Hypoglycemia can be caused by abnormal function of the hormones that regulate blood sugar or the inability of the body to store adequate amounts of glucose. Specific causes include insulinoma ( a tumor of the pancreas that produces excess insulin), overwhelming infection, an overdose of insulin used to treat diabetes, and hypoadrenocorticism (Addison's disease), a deficiency in hormones normally produced by the adrenal glands.
The signs and symptoms of hypoglycemia are similar regardless of the cause. These include lethargy, weakness, incoordination, seizures, nervousness, tremors, and hunger. In severe cases the patient may become unconscious.
A diagnosis of hypoglycemia as a cause of neurological problems is based on three criteria: (1) The patient has clinical signs of hypoglycemia, (2) A blood glucose concentration of less than 45 mg/dl is measured, and (3) The clinical signs go away when glucose is administered to the patient.
Once it is determined the neurological signs are due to hypoglycemia, the cause of the hypoglycemia must be found. In addition to a medical history and examination, laboratory tests are usually performed. If an insulinoma is suspected the insulin concentration in the blood can be measured. Hypoadrenocorticism can be diagnosed on the basis of measuring cortisol levels in the blood.
Emergency treatment of hypoglycemia involves administration of glucose. Usually this is done by intravenous injection. Giving a quickly absorbed source of sugar (syrup, honey, or jam) by mouth may be effective. Care should be taken when giving any substance by mouth to a patient that is seizing or unconscious as the substance may be inhaled into the lungs instead of being swallowed.
Any underlying cause of the hypoglycemia should be corrected if possible. Surgery is recommended in many cases of insulinoma. Medication is helpful in preventing low blood glucose in some patients. Dietary management usually entails frequent small meals consisting of food that is high in protein, fat, and complex carbohydrates. Paradoxically, frequent administration of simple sugars may be counterproductive as this often stimulates insulin production. This lowers blood glucose and may precipitate a hypoglycemic episode.
More information
