A coma is a state of deep unconsciousness. A person in a coma cannot react to events in the environment.
A coma needs emergency treatment right away.
Information about the environment is normally passed from the brainstem to the rest of the brain. This feedback allows a person to be aware of and react to the environment. A coma is caused by a breakdown in this system.
The doctor will gather information from friends, family members, or people who were there when symptoms started. The doctor will ask about the person's symptoms and health history, including any use of drugs or alcohol. A physical exam will be done. It will include tests of the nervous system.
Blood and urine tests will be done. The fluid around the brain and spine will also be tested. This can be done with a lumbar puncture.
Coma. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/coma. Accessed January 25, 2021.
Edlow JA, Rabinstein A, et al. Diagnosis of reversible causes of coma. Lancet. 2014 Dec 6;384(9959):2064-2076.
Last reviewed December 2020 by
EBSCO Medical Review Board
Rimas Lukas, MD
Last Updated: 1/25/2021
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