Coma and Persistent Vegetative State

A coma is a profound or deep state of unconsciousness. The person in a coma is alive but is not able to respond to life around him/her.


A coma may occur because of:

  • An expected result of an underlying illness.

  • Head trauma with bleeding and/or swelling of the brain.

  • Brain injury from bleeding and/or swelling caused by something that is not an injury. This can happen if a weak blood vessel or an aneurysm bursts in the brain.

  • A brain tumor can cause damage that can lead to bleeding and/or swelling.

  • Lack of oxygen to the brain. This could occur because of:

  • Severe pneumonia.

  • Severe emphysema.

  • Severe anemia.

  • A drowning incident.

  • Low blood sugar that is severe.

  • Poisoning and/or overdose from prescription or over-the-counter medicines.

  • Toxic effects of alcohol.

  • Toxic effects from the buildup of waste products in the blood as a result of kidney or liver failure.

Persistent Vegetative State

A persistent vegetative state sometimes follows a coma. It refers to a condition in which patients:

  • Have lost their thinking abilities.

  • Have lost awareness of their environment.

  • Retain non-cognitive function.

  • Sleep-wake cycle is preserved.

In persistent vegetative state the individual loses the higher powers of the brain. The functions of the brainstem remain relatively intact including:

  • Breathing.

  • Circulation.

Spontaneous movements may occur. The eyes may open in response to outside stimuli, but the patient does not speak or obey commands. Patients in a vegetative state may appear somewhat normal. They may sometimes grimace, cry, or laugh.


The most important first treatments focus on the injuries and/or diseases that caused the coma. Once the patient is out of immediate danger, but still in a coma or vegetative state, the medical care team concentrates on maintaining the patient's physical condition. This includes:

  • Preventing pneumonia.

  • Preventing bed sores.

  • Providing balanced nutrition.

Physical therapy may also be used to prevent:

  • Permanent muscular contractions (contractures).

  • Bone and joint (orthopedic) deformities that would delay recovery for the patients who come out of a coma.


The outcome for coma and vegetative state depends on the cause, severity, and extent of brain damage. Outcomes range from recovery to death. People may come out of a coma with a combination of difficulties that need special care including problems that are:

  • Physical.

  • Intellectual.

  • Psychological.

Recovery is usually gradual. Patients gain more and more ability to respond. Some patients never progress beyond very basic responses. Some patients recover full awareness. Patients recovering from coma require close medical supervision. A coma rarely lasts more than 2 to 4 weeks. Some patients may regain a degree of awareness after vegetative state. Others may remain in a vegetative state for years or even decades. The most common cause of death for a person in a vegetative state is infection such as pneumonia.