REM-associated nasal obstruction: A study with acoustic rhinometry during sleep

REM sleep is characterized by significant nasal congestion; non-REM sleep, by profound decongestion. This phenomenon may be attributable to REM-dependent variation in cerebral blood flow that affects nasal congestion via the internal carotid system. REM-induced nasal congestion, an indirect effect of augmented cerebral perfusion, may contribute to the higher frequency of obstructive events in REM sleep.