You've heard of people who walk or talk while they sleep, and you're probably familiar with night terrors, too. Believe it or not, some individuals actually have sex during slumber, and even have an orgasm while sound asleep.

Sexsomniacs don't remember anything about their night-time sexual exploits the next day, though, despite the fact that they engage in behaviors that range from fondling and masturbation to hyperarousal and actual sex.

So what's up with sexsomniacs? Here, the answers to a little understood sleep disorder.

1. How many people suffer from sexsomnia?

It's hard to know the exact figure, but it appears that 7.6 percent of the patients at sleep disorder centers have sexsomnia, according to a survey that looked at 832 people at a sleep disorder clinic. "There have been no previous studies of how frequently sexsomnia occurs," said Sharon A. Chung, a co-investigator in the study, who's in the department of psychiatry at the University Health Network in Toronto. "While our finding of 8 percent of people reporting sexsomnia seems really a high number, it should be stressed that we only studied patients referred to a sleep clinic. So, we would expect the numbers to be much lower in the general population."

2. Is sexsomnia more common in men or in women?

Sexsomnia is much more common in men than in women. Guys typically have sex with a partner and even may have an orgasm while snoozing, but don't remember doing so until they learn about it afterwards from their partner.

3. Do many people seek medical help for the condition?

No, they don't. In fact, just four of the 63 sexsomniacs in the survey had talked with a sleep specialist about their condition. That's too bad, since sexsomnia can be treated with medication, according to Carlos Schenck, a psychiatrist at the Minnesota Regional Sleep Disorders Center and the author of the book, Sleep: The Mysteries, the Problems, and The Solutions.  "The longer you go with this problem without getting it treated, the more you can then develop a secondary psychological problem," like depression, Schencksays.

4. What causes someone to initiate a middle of the night sexual romp?

Sexsomniacs, like other insomniacs, tend to consume caffeine and smoke cigarettes in similar fashion. But sexsomniacs were twice as likely as other insomniacs to report using illicit drugs.

5. Are there other risk factors for sexsomnia?

People who suffer from other sleep disorders like sleep walking and sleep terrors are definitely more prone to develop sexsomnia.

Sources

"Wide Range Of Sleep-Related Disorders Associated With Abnormal Sexual Behaviors, Experiences." 3 June 2007. Science Daily.

http://www.sciencedaily.com/releases/2007/06/070601072523.html

"Sexsomnia 'Sex While Sleeping' condition studied." 7 June 2010. LiveScience.

http://www.livescience.com/health/sexomnia-sex-while-sleeping-100607.html

"Have sex while you sleep," by Melinda Wenner. 2 June 2007. LiveScience.

http://www.livescience.com/health/070602_sleep_oddities.html