[Sleep and sexuality].

Our knowledge about the multiple aspects of sleep functions are still insufficient. Concerning the relationship between sleep and sexuality there are four points of view to take into account. Two observations: a spontaneous sexual excitement during REM sleep and that some anxious dreams can produce also sexual arousal. Two hypotheses: the erotic pleasure could be easier to perceive in a sleeping or dreaming state than in a waking state and some sleeping troubles could have an important influence on the sexual life of a couple.