Women may experience orgasm in their sleep,” also known as nocturnal, or sleep orgasms, Debby Herbenick, human sexuality scholar, and professor at the Indiana University School of Public Health says.
An estimated 37% of women (more accurately, people with vaginas) reported having at least one, according to a 1986 study, while 83% of men (penis havers) in the U.S. experienced them, per sex scholar Alfred Kinsey’s book, Sexual Behavior in the Human Male.
In fact, there are descriptions dating back more than a century of people across genders seeking help for their sleep orgasms, due to sexuality’s connection to religious guilt and shame in some cultures, Herbenick says.
Every night, you cycle through four stages of sleep a handful of times, per Michigan Medicine: stage 1, stage 2, stage 3, and rapid eye movement, or REM, sleep, when you tend to have vivid dreams.
REM sleep is associated with genital arousal, including penile erections and vaginal lubrication, Herbenick says. When men have an erotic dream while in REM sleep, they can ejaculate, the phenomenon is called a “wet dream.” Many people who report sleep orgasms also recall having erotic dreams, but you don’t necessarily need to have them to orgasm, according to Herbenick.
Women can climax in their sleep, too, even if they don’t leave the same physical trace, but although they report them, the laboratory research evidence is scant; sleep orgasms don’t happen with much frequency or predictability, making them hard to study, says Leah Millheiser, director of the Stanford Female Sexual Medicine Programme.
A 1983 study that included looking at the physiological changes in a woman during a sleep orgasm found that her breathing rate jumped from 12 to 22 breaths a minute, and her heart rate from 50 to 100 beats a minute, Splinter reports. She also had more blood flow to her vagina.
When a woman is awake, a stimulus, usually physical, in their genital region signals to a region of the brain called the genital sensory cortex, which then signals back to the genital region, triggering pleasure and eventually, orgasm, says Millheiser: “It’s a loop.” But if they’re asleep, imagery in the brain during a dream might also act as a stimulus.
This is consistent with a small 2016 brain imaging study conducted by the same Rutgers researchers who compared mental and physical orgasms, Splinter reports. They found that simply imagining touching the nipple or clitoris activated women’s genital sensory cortex as if they’d physically stimulated these body parts.