ABSTRACT.REM sleep can be easily identified in standard EEG montages by analysis of eye movements in sleep, and the method of visual analysis was described. The patient should be asked upon arousal whether or not dreaming has occurred. Identification of REM sleep is important, because it may indicate significant abnormality of the wake-sleep cycle. Overnight sleep deprivation alone may be sufficient to cause shortening of the REM latency. Common clinical features that were associated with REM sleep in standard EEGs, were reviewed. The hospital environment is particularly likely to interfere with the patients' wake-sleep cycle.