Nightmares are dreams that cause intense fear. These dreams are often complex and fairly long. During the dream, the sleeper usually encounters or experiences a threat to their life or safety. Nightmares are also reported that do not involve physical danger.During the course of a nightmare the sleeper may moan, talk, or move slightly, although these signs do not always appear. The person wakes from the nightmare with a profound sense of fear. Waking is complete, and usually accompanied by increased heart rate, sweating, and other symptoms of anxiety or fear. Once fully awake, the person usually has a good recall of the dream and what was so frightening about it.
Imagery rehearsal treatment is a promising cognitive behavioral therapy for recurrent nightmares and nightmares caused by PTSD. The technique helps chronic sufferers change their nightmares by rehearsing how they would like them to transpire. In some cases, medications may be used in conjunction with therapy to treat PTSD-related nightmares, though their efficacy has not been demonstrated as clearly as that of imagery rehearsal treatment.A literature review reports that up to 85% of adults report at least one nightmare within the previous year, 8-29% report monthly nightmares and 2-6% report weekly nightmares. Older people were 20-50% less likely to have nightmares than young people.