Parasomnias or sleep disorders are disruptive disorders that can occur during arousals from REM (rapid eye movement) sleep or partial arousals from Non-REM sleep. Parasomnias often include somnambulism or sleepwalking, nightmares, night terrors, confusional arousals and many others.
Types of Parasomnias
Nightmares
Nightmares are vivid nocturnal events that cause feelings of fear and terror, with or without feeling anxiety. In most cases, a person having a nightmare will be abruptly awakened from REM sleep and is able to give a detailed account of what he dreamt about. Also, the person having a nightmare has difficulty returning to sleep.