A coma is a state of prolonged unconsciousness that can be caused by a variety of problems — traumatic head injury, stroke, brain tumor, drug or alcohol intoxication, or even an underlying illness, such as diabetes or an infection.
A coma is a medical emergency. Swift action is needed to preserve life and brain function. Doctors normally order a battery of blood tests and a brain CT scan to try to determine what's causing the coma so that proper treatment can begin.
A coma seldom lasts longer than several weeks. People who are unconscious for a longer period of time may transition to a persistent vegetative state.
Depending on the cause of a coma, people who are in a persistent vegetative state for more than one year are extremely unlikely to awaken.
Aug. 14, 2015
- Overview of coma and impaired consciousness. The Merck Manual Professional Edition. http://www.merckmanuals.com/professional/neurologic-disorders/coma-and-impaired-consciousness/overview-of-coma-and-impaired-consciousness. Accessed July 15, 2015.
- Edlow JA, et al. Diagnosis of reversible causes of coma. The Lancet. 2014; 384:2064.
- Rosengart A, et al. Coma. In: Critical Care Medicine: Principles of Diagnosis and Management in the Adult. Philadelphia, Pa.: Elsevier; 2014. http://www.clinicalkey.com. Accessed July 15, 2015.
- Young GB. Stupor and coma in adults. http://www.uptodate.com/home. Accessed July 15, 2015.
- Daroff RB, et al. Bradley’s Neurology in Clinical Practice. 6th ed. Philadelphia, Pa.: Saunders Elsevier; 2012. http://www.clinicalkey.com Accessed July 15, 2015.
- NINDS coma information page. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/coma/coma.htm. Accessed July 15, 2015.
- Marx JA, et al. Rosen's Emergency Medicine: Concepts and Clinical Practice. 8th ed. Philadelphia, Pa.: Mosby Elsevier; 2014. http://www.clinicalkey.com. Accessed July 15, 2015.
- Rabinstein AA (expert opinion). Mayo Clinic, Rochester, Minn. July 20, 2015.