Coma is a state of prolonged unconsciousness

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.

Coma is a medical emergency. Swift action is needed to preserve life and brain function. Doctors normally order a series of blood tests and a brain 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 time might transition to a persistent vegetative state or brain death.


The signs and symptoms of a coma commonly include:

Closed eyes

Depressed brainstem reflexes, such as pupils not responding to light

No responses of limbs, except for reflex movements

No response to painful stimuli, except for reflex movements

Irregular breathing