• Reviewed on 12/12
    By Dr. Harrington

Parasomnias: Overview

Parasomnias are physical events that occur during sleep. They may or may not disrupt sleep. Often, it is the sleep partner who calls these events to the sleeper's attention.


Types of parasomnias include:

  • Confusional Arousals: Confusion and disorientation occur following arousals from sleep. This often happens in the first part of the night. There is often no memory of the event. Confusional arousals may be caused by lack of sleep. They may also be caused by abrupt awakenings from deep sleep.
  • Leg Cramps: A painful tightening of the muscles of the leg or foot awakens a person from sleep. Flexing or massaging the leg or foot relieves the sensation. Nighttime leg cramps are common. It may be more common among the elderly, during pregnancy, or after intense exercise.
  • Nightmares: Frightful dreams can quickly awaken the sleeper. Once awake, the person is fully alert. He or she can clearly remember the dream and is fearful and anxious. The person is unable to promptly return to sleep.
  • REM Sleep Behavior Disorder: Body movements occur with dreaming. They may be simple motions. They may also be highly complex acts such as screaming, punching, kicking, or running. These movements may result in sleep disruption and/or injury to the sleeper or sleep partner.
  • Rhythmic Movement Disorder: Repetitive movements of parts of the body start before falling asleep. They continue during early light sleep. This is called "head banging" if it involves motions of the head and neck. Other types include head rolling, body rolling, or body rocking. This is often seen in young children. Adolescent and adult cases are rare.
  • Sleep Starts: Sleep starts consist of abrupt jerks of parts of the body. These may startle a person out of sleep with a feeling of "falling" or "dreaming".
  • Sleep Talking: Words and sentences can be uttered during sleep. Sometimes, only unclear mumbles are heard.
  • Sleep Terror: A person having a sleep terror appears to quickly awaken from sleep with profound fear. The person bolts upright from bed crying or yelling, breathing heavily with heart pounding, and with increased sweating. Unlike nightmares, people have a poor memory of these episodes and are confused. Sleep terrors occur more often in the first third of the night. They are more common in children and tend to resolve by adolescence.
  • Sleepwalking: The sleepwalker is difficult to arouse, may display "bizarre" behavior, and has little memory of the event. Sleepwalking can lead to physical injuries to the sleeping person. Sleepwalking is most often seen in young children. It is less common among adults.



Parasomnias, including sleepwalking and sleep terrors, are more common in children. They usually resolve as the child grows, and do not often require treatment. Other parasomnias, such as REM sleep behavior disorder, can cause major safety risks, and often require treatment. To help identify this and see if treatment is needed, ask your doctor.  


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