Health Dictionary Find a Doctor

Coma overview

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [3] Associate Editor(s)-in-Chief: Raviteja Guddeti, M.B.B.S.[4]

Overview

Overview

In medicine, a coma (from the Greek Template:Polytonic koma, meaning deep sleep) is a profound state of unconsciousness. A comatose patient cannot be awakened, fails to respond normally to pain or light, does not have sleep-wake cycles, and does not take voluntary actions. Coma may result from a variety of conditions, including intoxication, metabolic abnormalities, central nervous system diseases, acute neurologic injuries such as stroke, and hypoxia. It may also be deliberately induced by pharmaceutical agents in order to preserve higher brain function following another form of brain trauma, or to save the patient from extreme pain during healing of injuries or diseases. A coma may also result from immense head trauma caused by something like a car accident or a series of very severe concussions. The underlying cause of the coma is bilateral damage to the reticular formation of the midbrain, which is important in regulating sleep.[1]

Diagnosis

Diagnosis

Physical Examination

Neurological examination and eye examination are very useful to identify underlying problem in the brain.

Laboratory Findings

Laboratory tests include the check of liver function, kidney function, glucose levels, thyroid function, even the presence of any toxins. The results of the various lab tests may provide clues to detect some metabolic diseases which can cause coma.

CT

CT images can be used to detect the abnormalities in the brain.

MRI

MRI images can be used to detect the abnormalities in the brain.

Other Diagnostic Studies

Electroencephalography (EEG) test can demonstrate the electrical activity in the brain and be used to rule out seizures.

Treatment

Treatment

Surgery

Treatments depend on the underlying cause. Emergent surgery is needed for a hemorrhage stroke.

References

References

  1. The Human Brain: an introduction to its functional anatomy 5th ed by J Nolte chpt 11 pp262-290

Template:WH Template:WS

Looking for the patient version?

Back to the patient-friendly article

© 2026 MyEClinic – IFTM Institut für Telematik in der Medizin GmbH