A coma is generally understood to be a state of unconsciousness from which a patient cannot be awakened. While unconscious, the patient is unable to engage in voluntary actions, does not exhibit a cycle of waking and sleeping, and does not register any reaction to any type of stimulus. Essentially, the comatose patient remains alive, but is completely unable to relate to the world at large.
Drawing the name from the Greek word koma, which means deep sleep, a coma can result from a number of different events. Problems with the central nervous system can invoke a coma. Medical crises such as a stroke may also result in the patient entering a comatose state. There are instances where intoxication resulted in the individual falling into a coma for an extended period.
Accidents may also result in a coma. Any type of accident that involves head trauma has the potential to result in the individual becoming unconscious and sinking into a coma. This is especially true of a concussion is suspected. Generally, this is attributed to damage to the section of the brain known as the reticular formation. It is this area of the brain that helps to regulate the daily cycle of wakefulness and sleep.
There are also examples of medically induced comas as well. For example, a health care professional may choose to use medication to induce a coma if there has been a severe head trauma that must be addressed. Doing so is understood to help protect higher brain function from both the trauma and the medical procedures that may be necessary to effect recover.
While most people understand a coma as being a state where the individual is completely still and silent, that is not always the case. In some instances, the comatose patient may exhibit some involuntary movement that appears to be voluntary. There is also the possibility of the patient vocalizing from time to time. However, all these actions are not under the control of the individual, and do not necessarily indicate that he or she is becoming more aware of the surroundings.
Comas often last anywhere from a few days to several weeks. Recovery from the coma usually takes some time, as the patient slowly regains control of motor functions and is able to recapture speech and other communication skills. In some cases, full recovery does not take place. In other instances, the individual may enter what is known as a vegetative state or perhaps never regain consciousness and expire.
While medical science has produced coma treatments that have been successful in some cases, there is no exact treatment for dealing with a coma. Healthcare professionals approach each case on an individual basis, and formulate the treatment based on known factors that relate to the patient.