<unk>  (NCT) is a spontaneous swelling of the clitoris during sleep or when waking up. Similar to the process in males, nocturnal penile<unk> , females experience clitoris<unk>  or engorgement of the vagina mainly during REM sleep phase. According to Fisher et al., the increase in vaginal blood flow associated with NCT during REM sleep is similar to the process in man in frequency, i.e. 95% of REM phases. It does occur a bit more often in non-REM sleep, and each episode appears shorter in duration. In terms of magnitude, NCT is similar to that induced by erotic stimulation when awake. The phenomenon was first documented in 1970 by Karacan et al., with a single aforementioned follow-up study in 1983 by Fisher et al.
Nocturnal clitoral tumescence
Nocturnal penile tumescence
Task-invoked pupillary response
Morning pseudoneutropenia
Clitoral erection
Premenstrual water retention
Nocturnal enuresis
Apraxia of lid opening