Nightmare disorder, which is also called dream anxiety disorder, is characterized by the occurrence of repeated dreams during which the sleeper feels threatened and frightened. The sense of fear causes the person to awake.
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.
As the dream progresses, the threat to the person usually increases, as does their sense of fear. Waking usually occurs just as the threat or danger reaches its climax. It is often difficult for a person to return to sleep after waking from a nightmare. Nightmares usually occur during the second half of the night's sleep.
Causes and symptoms
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. Because of the physical symptoms of anxiety and because clarity is achieved immediately upon waking, returning to sleep after a nightmare is often difficult. The vividness of the recall and the prominence of the dream images in the person's mind can also make it difficult to calm down and return to sleep.
Sometimes people may avoid going to sleep after a particularly intense nightmare because of the fear of having another bad dream. In addition, people may have problems falling asleep if they are experiencing anxiety caused by the fear of having nightmares. As a result, these people may have the signs and symptoms associated with mild sleep deprivation, such as decreased mental clarity, problems paying attention, excessive daytime sleepiness, irritability, or mild depression.