Parasomnias

A parasomnia is any sleep disorder such as sleepwalking, night terrors, rhythmic movement disorder, REM behaviour disorder, restless leg syndrome, and sleep talking or somniloquy, characterized by partial arousals during sleep or during transitions between wakefulness and sleep. Parasomnias are often associated with stress and depression, and biological factors may also be involved. Many parasomnias are more common in children than in adults.

Many parasomnias, such as sleepwalking, are often used as themes in comedy, but can actually have serious consequences. For example, a person with REM behavior disorder, while trying to swing a tennis racket in a dream, can potentially injure their bedmate. People with night terrors can prevent others from sleeping well, as well as waking themselves up. For these reasons, parasomniacs sometimes need medical treatment.