A coma is a deep state of unconsciousness where the affected individual is alive but is not able to react or respond to life around him/her.     

Sometimes comatose patients    are totally unaware of their states and environments; sometimes they are partially or fully aware but cannot communicate

Coma is not a disease. It is a symptom of a disease or a response to an event, such as a severe head injury, seizure or metabolic problem.

No one can tell you when he/she will wake up. You can only WAIT and SEE. Furthermore, head injured persons rarely wake up all at once.

Most comas last no longer than four weeks. Some people in a coma shift to a persistent vegetative state,

  There is

  Lack of consciousness
  Lack of self-awareness
  Lack of sleep-wake cycle
  Lack of purposeful movements

Head injury or certain serious illnesses or their complications may cause a coma. The most common causes of coma include: Severe head injury Seizures Metabolic disturbances, such as low or high blood sugar Tumors or other structural lesions leading to high pressure within the skull Bleeding in the brain Alcohol or drug intoxication

Many of the head injuries that cause comas can be prevented through safety practices, such as wearing seatbelts in cars and helmets on bicycles and motorcycles. Routine doctor visits will lessen the chances of coma in patients with diabetes, seizure disorders or other conditions that may lead to coma.

Vital signs (temperature, pulse, respiratory rate and blood pressure) and inquires about the patient's medical history and the circumstances under which the coma occurred. · Blood to be tested for levels of electrolytes, glucose, calcium, magnesium, arterial blood gases, and liver and kidney function. · Check the patient's heart with an electrocardiogram or the patient's brain with an Electroencephalography (EEG). An EEG may also be used to provide repetitive sensory stimulation so that the doctor can determine nerve response (evoked potentials or EPs). · If increased pressure within the skull is evident or suspected, the doctor may request a Computerized Tomography Scan (CT scan) or Magnetic Resonance Imaging (MRI) of the brain. · In some instances, a spinal tap is performed; this involves using a needle to withdraw fluid from around the spine for testing.

Some lesions in the brain may have the same texture as surrounding tissue and might not be identified in a CT. It may not show on the MRI also until it evolves fully and hence might not be seen immediately.

Initial emergency treatment of a comatose patient focuses on stabilizing the vital signs. This may rapidly reverse the coma.

The specific cause of the coma has to be treated.
1. A complementary treatment goal is
     . to prevent infection and,
     · as possible, maintain the patient's physical state
     · preventing pneumonia · preventing bedsores
     · providing balanced nutrition.
     · Physical therapy may prevent permanent muscle 
       contractions and bone deformities.
2. If doctors think the coma is not likely to reverse quickly, they may insert an endotracheal tube to aid respiration and may administer oxygen

In the case of a coma that results from a head injury, doctors may perform surgery to drain excess fluid from the head and relieve pressure on the brain.

People who wake and sleep but have no meaningful interaction with the world around them are said to be in PERSISTENT VEGETATIVE STATE

The prognosis for regaining full mental faculties once the vegetative state has supervened is almost negligible. Most instances of dramatic recovery, when investigated carefully, yield to the usual rules for prognosis, but it must be acknowledged that rare instances of awakening to a condition of dementia or paralysis after months or years in this state have been documented.

A number scale called the Glasgow Coma Scale is often used to describe the responses of people in coma. There is nothing magic about this scale; it just attaches numbers to the responsiveness of the head injured person in terms of eye opening, speaking, and moving his/her extremities. People are usually no longer considered to be in coma if they open their eyes, speak, or can obey simple commands.

People who are in coma cannot obey commands. They may move, however, in response to touch or pain, or even on their own.