Nightmare disorder

Nightmare disorder, also known as "dream anxiety disorder", is a sleep disorder characterized by frequent nightmares. The nightmares, which often portray the individual in a situation that jeopardizes their life or personal safety, usually occur during the second half of the sleeping process, called the REM stage. Though such nightmares occur within many people, those with nightmare disorder experience them with a greater frequency. The disorder's DSM-IV number is 307.47.
In some cases it could be brought on by the content of home life,movies,books and music that you let yourself consume. Most people with nightmare disorder or usually pessimistic or experiencing bad thoughts throughout the day which can be collected in the dream state to create what they witness in their dreams.