Your penis painfully curves when it becomes erect. You N ature plays a cruel joke when the body's main source of pleasure becomes a focus of pain. Penile pain comes in several forms, most of which are apparent only when the penis is erect. Prolonged penile swelling, called priapism, may start out as a normal erection, and it may look like one, but it actually isn't. What we're really looking at is a malfunction of the regulation of blood flow in and out of the penis.
Priapism usually results from an injury or a medication.
Some men with diabetes or sickle cell disease also are prone to priapism, according to Bruce H. Blank, M.D., a clinical associate professor at Oregon Health Sciences University School of Medicine in Portland. An injury can actually break an erect penis, causing pain and even priapism. I've seen people who've had a door slam on their penises while having sex in a car. It's also possible to miss the vagina during intercourse, cracking the erection against the woman's pelvis or thigh. It just breaks.