A patient in a coma is not sedated but
shows no sign of wakefulness or awareness of themselves or of their environment.
Their eyes will be closed and they will not respond to commands or verbal or
painful stimuli.
A coma may persist for a few hours or several weeks and there
have been a few extreme cases that have lasted for years. A person may awaken
from a coma, or progress to a vegetative or
minimally conscious
state.