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Definition
By Mayo Clinic staffComa 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.
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.
Comas seldom last 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 coma, people who are in a persistent vegetative state for more than one year are extremely unlikely to awaken.
- Goldman L, et al. Cecil Medicine. 24th ed. Philadelphia, Pa.: Saunders Elsevier; 2012. http://www.mdconsult.com/das/book/body/191371208-2/0/1492/0.html#. Accessed Aug. 24, 2012.
- Daroff RB, et al. Neurology in Clinical Practice. 6th ed. Philadelphia, Pa.: Saunders Elsevier; 2012. http://www.mdconsult.com/books/about.do?about=true&eid=4-u1.0-B978-1-4377-0434-1..C2009-0-40427-6--TOP&isbn=978-1-4377-0434-1&uniqId=364938937-2. Accessed Aug. 28, 2012.
- Young GB. Stupor and coma in adults. http://www.uptodate.com/index. Accessed Aug. 24, 2012.
- Overview of coma and impaired consciousness. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merckmanuals.com/professional/neurologic_disorders/coma_and_impaired_consciousness/overview_of_coma_and_impaired_consciousness.html?qt=coma&alt=sh. Accessed Aug. 24, 2012.
- Traumatic brain injury: Hope through research. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/tbi/tbi.htm. Accessed Aug. 27, 2012.
- NINDS cerebral hypoxia information page. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/anoxia/anoxia.htm. Accessed Aug. 27, 2012.
- Diabetes, heart disease, and stroke. National Diabetes Information Clearinghouse. http://diabetes.niddk.nih.gov/dm/pubs/stroke/index.aspx. Accessed Aug. 27, 2012.
- Meningitis and encephalitis fact sheet. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/encephalitis_meningitis/encephalitis_meningitis.htm. Accessed Aug. 27, 2012.
- Stroke: Hope through research. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/stroke/stroke.htm. Accessed Aug. 27, 2012.
- Neurological diagnostic tests and procedures. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/misc/diagnostic_tests.htm. Accessed Aug. 27, 2012.
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