Regular masturbation or sex with ejaculation helps reduce the frequency of nocturnal emissions, advises WebMD. For some males, the release of semen during waking hours prevents a retention of fluid that expels during sleep.
According to the University of California, Santa Barbara, nocturnal emissions begin at puberty. In a nocturnal emission, the penis is erect and releases ejaculation during sleep. Masturbation is not necessary for a release to occur. Some males wake up when a nocturnal emission occurs, while many others remain asleep. There is a difference between a nocturnal orgasm and a nocturnal emission, and the two do not necessarily occur together. A "wet dream" is another term for a nocturnal emission.