SymptomsBy Mayo Clinic staff
Your body needs a steady supply of sugar (glucose) in order to function properly. If glucose levels become too low, as occurs with hypoglycemia, it can have these effects on your brain:
- Confusion, abnormal behavior or both, such as the inability to complete routine tasks
- Visual disturbances, such as double vision and blurred vision
- Seizures, though uncommon
- Loss of consciousness, though uncommon
Hypoglycemia may also cause these other signs and symptoms:
- Heart palpitations
- Tingling sensation around the mouth
These signs and symptoms aren't specific to hypoglycemia. There may be other causes. An intravenous blood sample to test your blood sugar level at the time of these signs and symptoms is the only way to know for sure that hypoglycemia is the cause.
When to see a doctor
Seek a doctor's help immediately if:
- You have what appears to be symptoms of hypoglycemia. Hypoglycemia, if confirmed, can be an indication of any number of illnesses, all of which can be serious.
- You have diabetes and early signs of hypoglycemia don't improve with eating or taking glucose tablets.
- Seek emergency help if someone you know who has diabetes or a history of recurring hypoglycemia loses consciousness.
- Patient guide on the diagnosis and management of hypoglycemic disorders (low blood sugar) in adults. The Hormone Foundation. http://www.hormone.org/Resources/upload/patient-guide-diagnosis-and-management-hypoglycemia-022509.pdf. Accessed Nov. 12, 2011.
- Aminoff MJ, et al. Disorders of cognitive function. Clinical Neurology. 7th ed. New York, N.Y.: The McGraw-Hill Companies; 2011. http://www.accessmedicine.com/content.aspx?aID=5143601.
Accessed Nov. 16, 2011.
- Hypoglycemia. National Institute of Diabetes and Digestive and Kidney Diseases. http://diabetes.niddk.nih.gov/dm/pubs/hypoglycemia/index.htm. Accessed Nov. 13, 2011.
- Hypoglycemia (low blood glucose). American Diabetes Association. http://www.diabetes.org/living-with-diabetes/treatment-and-care/blood-glucose-control/hypoglycemia-low-blood.html. Accessed Nov. 13, 2011.
- Cryer PE, et al. Hypoglycemia. In: Longo DL, et al. Harrison's Online. 18th ed. New York, N.Y.: The McGraw-Hill Companies; 2012. http://www.accessmedicine.com/content.aspx?aID=9141631. Accessed Nov. 16, 2011.
- Josefson J, et al. Hypoglycemia in the emergency department. Clinical Pediatric Emergency Medicine. 2009;10:285.
- Cryer PE. Hypoglycemia in type 1 diabetes mellitus. Endocrinology and Metabolism Clinics of North America. 2010;39:641.
- Masharani U, et al. Pancreatic hormones and diabetes mellitus. In: Gardner DG, et al. Greenspan's Basic & Clinical Endocrinology. 9th ed. New York, N.Y.: The McGraw-Hill Companies; 2011. http://www.accessmedicine.com/content.aspx?aID=8407307. Accessed Nov. 16, 2011.
- Goyal N, et al. Type 1 diabetes mellitus. In: Tintinalli JE, et al. Tintinalli's Emergency Medicine: A Comprehensive Study Guide. 7th ed. New York, N.Y.: The McGraw-Hill Companies; 2011. http://www.accessmedicine.com/content.aspx?aID=6379758. Accessed Nov. 16, 2011.
- Vella A, et al. Hypoglycemia and pancreatic islet cell disorders. In: Goldman L, et al. Goldman's Cecil Medicine. 24th ed. Philadelphia, Pa.: Saunders Elsevier; 2011. http://www.mdconsult.com/books/page.do?eid=4-u1.0-B978-1-4377-1604-7..00238-4&isbn=978-1-4377-1604-7&uniqId=303466088-3#4-u1.0-B978-1-4377-1604-7..00238-4--s0010. Accessed Nov. 21, 2011.
- Service FJ (expert opinion). Mayo Clinic, Rochester, Minn. Nov. 18, 2011.