reaction to exposure to extreme stress. The reaction is manifested by extreme feelings of fear. Begins fairly soon after the traumatic event and lasts at most four weeks. Is also manifested by reliving the event in dreams or flashbacks.

A reaction sometimes observed in individuals who have experienced a traumatic event that is characterized by recurrent nightmares and waking flashbacks of the traumatic event.

An anxiety disorder that involves vivid, repeated memories of a painful and upsetting event, feelings of agitation, and irritability, often leading to avoidance. Symptoms begin in the first month after the event and last up to 4 weeks.