Parasomnias are REM related and non REM related. REM and non REM (NREM) are different stages of normal sleep. Parasomnias are abnormal movements or behaviours associated with these stages of sleep.

Examples of NREM parasomnias include confusional arousals, sleep walking and sleep terrors. These conditions tend to be more common in childhood, and often lessen as the sufferers approach adulthood. However, when they persist or recur as adults they can be quite troublesome. Sleep walkers may hurt themselves at night time especially with stairs and balconies. At times sleep walking may be associated with "sleep eating". There are some adult triggers for these conditions that need to be considered, including medications and other sleep disorders. NREM parasomnias are readily treated with environmental modification and medications (if required).

Examples of REM parasomnias include REM behaviour disorder and recurrent isolated sleep paralysis. REM behaviour disorder often affects middle aged men and is associated with them acting out their dreams. At times their movements can be very violent causing injury to themselves (hitting or thrashing at walls or the bed) or their partners. Careful medical assessment is required for underlying causes and associated neurological disorders.  Medications can be prescribed if necessary to control the symptoms.

Some parasomnias occur secondary to commonly prescribed medications.

A careful sleep disorders history and assessment is required to assess the type of parasomnia; possible causes and triggers; and to guide treatment. Treatment of parasomnias involves reducing triggers, environmental modification and in some cases medications.