CBSE Class 12-science Answered
Coma is a prolonged state of unconsciousness where a person is unresponsive to his or her environment. The person is alive and looks like he or she is sleeping. However, unlike in a deep sleep, the person cannot be awakened by any stimulation, including pain. Comas are caused by an injury to the brain. Brain injury can be due to increased pressure, bleeding, loss of oxygen or build-up of toxins.