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 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.

Symptoms Causes Complications

The signs and symptoms of 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

When to see a doctor

Coma is a medical emergency. Seek immediate medical care.

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