Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Coma ?
    ### Response:
    A coma, sometimes also called persistent vegetative state, is a profound or deep state of unconsciousness. Persistent vegetative state is not brain-death. An individual in a state of coma is alive but unable to move or respond to his or her environment. Coma may occur as a complication of an underlying illness, or as a result of injuries, such as head trauma.
    