What is a coma?

A coma is a state of deep unconsciousness. A person in a coma may appear to be asleep but cannot be awakened. The person will not speak, move on purpose, or respond to loud noises, touch, or shaking.

Some people in a coma breathe on their own. Others need a breathing machine to breathe for them.

What is the cause?

Coma can happen when a serious illness or injury damages the brain or spinal cord. Coma may result from:

  • Accidents or blows to the head
  • Bleeding in the brain or inside the skull
  • Infections
  • Seizures
  • Tumors
  • Drug or alcohol overdose
  • Stroke
  • Lack of oxygen that may happen with severe blood loss, very low blood pressure, severe lung disease, carbon monoxide poisoning, or if the heart stops beating for too long
  • Severe imbalance of chemicals in the body

How is it diagnosed?

To help find the cause of the coma, tests may include:

  • Blood tests
  • CT scan, which uses X-rays and a computer to show detailed pictures of the brain
  • EEG (electroencephalography), which measures and records the electrical activity in your brain
  • Lumbar puncture, also called a spinal tap, which uses a needle to get a sample of fluid from the area around your spinal cord
  • MRI, which uses a strong magnetic field and radio waves to show detailed pictures of the brain

How is it treated?

Most people who are in a coma need intensive care at first. They often need a machine to help them breathe. Medicines, nutrition, and fluid can be given through an IV or through a feeding tube. Family or nursing help is needed for skin care, eye care (to prevent dryness), gentle exercising of the arms and legs, and bowel and bladder functions.

Treating infections, stopping sedative drugs, or removing pressure on the brain are other possible treatments. After being in a coma, such as after a bad stroke or an infection that affects the brain, the person may need rehabilitation therapy.

If the cause of coma is found and treated quickly, most people recover fully. Some recover but have permanent brain damage. Some people die without ever waking up.

If someone is in a coma, it is important to find out if they have an advance directive, or living will. Advance directives are written instructions about what kind of medical care a person wants if they are not able to make decisions. They go into effect when a person is no longer able to speak for himself or herself. An advance directive spells out how much should be done to keep a person alive if they may never come out of a coma. This is a very hard decision for a family to make. Knowing what the person wants helps the family make decisions about their care.

Developed by RelayHealth.
Adult Advisor 2015.1 published by RelayHealth.
Last modified: 2014-03-04
Last reviewed: 2014-05-07
This content is reviewed periodically and is subject to change as new health information becomes available. The information is intended to inform and educate and is not a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional.
Copyright ©1986-2015 McKesson Corporation and/or one of its subsidiaries. All rights reserved.

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