Sex is a beautiful thing. It can also be difficult, terrifying or painful for some. Here are 10 such disorders that ruin sex for the people who have them.

10. Priapism

You know how at the tail end of Viagra commercials, after the previously limp man is happy and suggestively smiling with a woman, doing activities that aren’t sex related at all, that voice comes on and quickly states some side effects along with the phrase “if you have an erection that lasts more than 4 hours, seek help?” Well, that’s referring to priapism, a disorder that occurs when blood flows into the penis, but not out. It’s considered a medical emergency, and can lead to erectile disfunction, a disfigured penis and, in extreme cases, gangrene of the penis. We all know how gangrene is treated, right?

9. NREM Arousal Parasomnia

That’s a fancy way of saying “sleep sex.” People who suffer from sexsomnia engage in sexual activity while in the depths of REM sleep. It’s terrifying on many fronts, especially considering the dubiousness of consent in that situation: both yours and that of your potential partner. Sexsomnia sufferers have been convicted of sexual assault, though sometimes their condition has also worked as a legal defense.

8. Persistent Genital Arousal Disorder

Also known as PGAD, Weiss Disease or restless genital syndrome, persistent genital arousal disorder may sound fun for women, but it’s actually a horribly inconvenient and damaging disorder. It was just recently identified in 2001, so not much is known about what causes it. It’s most commonly found in people who have undergone hormone-therapy and menopausal women. A brief reprieve can be achieved through orgasm, but those genitals can become restless again as quickly as a few minutes.