Glucose serves as the primary fuel for the human body, providing the energy needed for movement and the metabolic functions that sustain life. The body possesses several mechanisms to maintain adequate availability of glucose in the bloodstream. A profoundly low blood glucose, or hypoglycemia, requires urgent intervention to prevent serious consequences, such as coma, organ damage or death.
Control Mechanisms
The body stores excess dietary glucose in the form of glycogen. When the blood glucose concentration declines to a low level, the pancreas releases the hormone glucagon, which triggers the breakdown of glycogen into glucose, explains the National Institute of Diabetes and Digestive and Kidney Diseases.
A precipitous or profound decrease in the blood glucose level also commonly provokes release of the hormone epinephrine from the adrenal glands. Similar to glucagon, epinephrine increases the conversion of glycogen to glucose. Depletion of the body glycogen stores leads to the manufacture of glucose by the liver. This manufacturing process, however, may prove inadequate to provide sufficient glucose to maintain a normal blood sugar level and hypoglycemia may occur.
Causes
Most episodes of hypoglycemia occur in reaction to diabetes medicines. Insulin, glyburide, glipizide, tolazamide, repaglinide, chlorpropamide, glimepiride, tolbutamide, glyburide, acetohexamide, nateglinide and mitiglinide may cause a hypoglycemic reaction, reports the National Library of Medicine encyclopedia MedlinePlus.
Metabolic conditions that reduce the rate of glucose production or increase the rate of glucose utilization can also provoke episodic hypoglycemia. Infants and young children with genetic abnormalities of certain enzymes, such as glucose-6-phosphatase, glycogen synthetase and liver phosphorylase, typically experience low blood glucose levels due to defective glucose production, notes the medical reference text "Harrison's Principles of Internal Medicine." Medical conditions that may cause hypoglycemia in adults include alcoholism, an insulin-producing tumor, severe liver disease, profound malnutrition and adrenal and pituitary gland deficiencies.
Symptoms
A blood glucose level less than 70 mg/dL represents hypoglycemia, notes MedlinePlus. Common symptoms of hypoglycemia include weakness, trembling, lack of coordination, moodiness or irritability, sweating, paleness, headache, hunger, inability to focus and confusion, reports the American Diabetes Association. Seizures, fainting and coma may occur.
Acute Treatment
Restoration of a normal blood glucose level is the goal of treatment for a patient with an acute hypoglycemic episode. In conscious patients, eating a rapidly absorbed form of glucose -- such as sugar tablets, hard candy, fruit juice, sugar water or honey -- usually raises the blood sugar to a normal level. Patients with impaired consciousness require intravenous glucose or an injection of glucagon, reports MayoClinic.com.
Long-term Management
Patients with diabetes mellitus should adhere to a diabetic meal plan, take medications as directed, avoid alcohol consumption and test their blood glucose level throughout the day to help prevent hypoglycemic episodes, notes the National Institute of Diabetes and Digestive and Kidney Diseases.
Treatment for ongoing hypoglycemia unrelated to diabetes medicines varies, depending on the underlying medical condition. Possible options include dietary changes, surgery and medications.
References
- National Institute of Diabetes and Digestive and Kidney Diseases: Hypoglycemia
- MedlinePlus: Hypoglycemia
- "Harrison's Principles of Internal Medicine, 16th Edition"; Dennis L. Kasper, M.D., et al., Editors; 2004
- American Diabetes Association: Hypoglycemia (Low Blood Glucose)
- MayoClinic.com: Hypoglycemia, Treatments and Drugs
