A coma is when a person is completely unresponsive and cannot be aroused for a significant length of time. Stupor is when reactions may be slower or it is more difficult to arouse a person. Often stupor and coma have similar symptoms and the doctor may have difficulty determining the cause, but with stupor the patient can be aroused. The term stupor often covers any condition with impaired consciousness, such as a drunken stupor. Because the person can ultimately be aroused with stimulation, stupor may be a less life-threatening condition.