In medicine, a coma, or comatose, (from the Greek koma, meaning deep sleep) is a profound state of unconsciousness. A comatose person can't be awakened, fails to respond normally to pain, light or sound, doesn't have sleep-wake cycles, and doesn't take voluntary actions. Coma may result from a variety of conditions, including intoxication, metabolic abnormalities, central nervous system diseases, acute neurologic injuries such as stroke, and hypoxia. A coma may also result from head trauma caus… (More on Coma)