A sudden or forceful bending of the penis while it's filled with blood, also known as erect, can cause a fracture. A fracture is a tear in the outer lining of one of the two cylinders that hold the blood while the penis is erect. Penile fracture mostly occurs during sexual intercourse.

These might include pain in the penis, a popping or cracking sound, and loss of erection. The penis might swell and change colors.

Penile fracture requires urgent medical care, usually surgery. If untreated, the penis might be curved. And it might not be able to become firm enough for sex.