Definition of NREM sleep
NREM sleep: NREM (non-rapid eye movement) sleep is dreamless sleep. During NREM, the brain waves on the electroencephalographic (EEG) recording are typically slow and of high voltage, the breathing and heart rate are slow and regular, the blood pressure is low, and the sleeper is relatively still. NREM sleep is divided into 4 stages of increasing depth leading to REM sleep.
REM sleep is when dreams occur. We have 3 to 5 REM periods per night. They occur at intervals of 1-2 hours apart and are quite variable in length, ranging from 5 minutes to over an hour. REM sleep is characterized by rapid, low-voltage brain waves, irregular breathing and heart rate and involuntary muscle jerks.
About 80% of sleep is NREM sleep. If you sleep 7-8 hours a night, all but maybe an hour and a half is spent in dreamless NREM sleep.
Last Editorial Review: 3/15/1999 8:40:00 PM
- hydroxyzine, Vistaril, Atarax - Specifies the medication hydroxyzine (Vistaril, Atarax), a drug used for the relief of nasal and non-nasal symptoms of various allergic conditions such as seasonal allergic rhinitis.
- Sinus Surgery (Patient Instructions) - Sinus surgery involves the precise removal of diseased sinus tissue with the improvement in the natural drainage channels by the creation of a pathway for infected material to drain from the sinus cavities. The sinus surgery information is provided to help you prepare for sinus surgery and to help you understand more clearly the associated benefits, risks, and complications.
- Bed Bugs - Learn what bed bugs (Cimicidae) look like, how they spread, how to treat, kill and detect an infestation (at home, hotel), where they come from and bite symptoms.
Latest Medical News

Back to MedTerms online medical dictionary A-Z List