REM sleep behavior disorder

Rapid eye movement (REM) sleep behavior disorder is a sleep disorder in which you physically act out vivid, often unpleasant dreams with vocal sounds and sudden, often violent arm and leg movements during REM sleep — sometimes called dream-enacting behavior.

You normally don't move during REM sleep, a normal stage of sleep that occurs many times during the night. About 20 percent of your sleep is spent in REM sleep, the usual time for dreaming, which occurs primarily during the second half of the night.

The onset of REM sleep behavior disorder is often sudden, and episodes may occur occasionally or several times a night. The disorder can get worse with time.

REM sleep behavior disorder often may be associated with other neurological conditions, such as Lewy body dementia (also called dementia with Lewy bodies), Parkinson's disease or multiple system atrophy.

Symptoms Causes Risk factors Complications

With REM sleep behavior disorder, instead of experiencing the normal temporary paralysis of your arms and legs (atonia) during REM sleep, you physically act out your dreams.

Symptoms of REM sleep behavior disorder may include:

  • Movement, such as kicking, punching, arm flailing or jumping from bed in response to the content of action-filled or violent dreams, such as being chased or defending yourself from an attack
  • Noises, such as talking, laughing, shouting, emotional outcries or even profanity
  • Being able to recall the dream if you are woken up during the episode

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