- Rapid eye movement sleep
- Rapid eye movement sleep (REM) sleep is the portion of sleep when there are rapid eye movements (REMs). Dreams occur during REM sleep. We typically have 3 to 5 periods of REM sleep per night. They occur at intervals of 1-2 hours and are quite variable in length. An episode of REM sleep may last 5 minutes or over an hour. About 20% of sleep is REM sleep. If you sleep 7-8 hours a night, perhaps an hour and half of that time, 90 minutes, is REM sleep. REM sleep is characterized by a number of other features including rapid, low-voltage brain waves detectable on the electroencephalographic (EEG) recording, irregular breathing and heart rate and involuntary muscle jerks.
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* * *REM sleep the period of sleep during which the brain waves are fast and of low voltage, and autonomic activities, such as heart rate and respiration, are irregular. This type of sleep is associated with dreaming, mild involuntary muscle jerks, and rapid eye movements (REM). It usually occurs three to four times each night at intervals of 80 to 120 minutes, each occurrence lasting from 5 minutes to more than an hour. In adults, about 20 per cent of sleep is REM sleep and 80 per cent is NREM (nonâ€“rapid eye movement) sleep. Called also desynchronized, dreaming, or paradoxical s. See also REM rebound, under rebound.
Medical dictionary. 2011.