It's the stuff of nightmares, and like a bad dream, it can happen to anyone. Unlike a bad dream, however, it can have actual consequence.

"It" is penile fracture, a rather vague term describing the disquieting and blunt affliction of a "broken" penis. It's apparently rare — there are less than 2,000 cases reported in medical literature, according to one 2004 study — but it can certainly happen. And from harrowing play-by-play accounts, it's no fun.

Misconceptions and doubt hover around the issue: Can you really break your penis if there's no bone in it? Well, to a pun-y extent, that's a valid question. Most penile fractures occur during sexual intercourse, during which, presumably, a man's member is engorged with blood and erect. And it's during all that activity — particularly of the "woman-on-top" variety, according to one study — that the penis can become overextended and fracture.

It happens with a "snap" or a "crack," medical experts say. "With a real penile fracture, you will immediately experience a popping sound and then lose the erection right away," Dr. Darius Paduch, Ph.D., urologist and male sexual medicine specialist at New York Presbyterian/Weill Cornell Medical Center told BuzzFeed.

Hunter Wessells, who chairs the University of Washington School of Medicine's urology department, described what actually happens during a fracture in an interview with Scientific American.

[P]enile fracture... occurs when a membrane called the tunica albuginea tears. The tunica albuginea surrounds the corpora cavernosa, specialized spongy tissue in the core of the penis that fills up with blood during an erection. When the tunica albuginea tears, the blood that is normally confined to this space leaks out into other tissues. You get bruising and swelling.

Flickr/Alice Henneman - flickr.com

Fractures are serious and painful, according to firsthand accounts, and can involve swelling so severe that the penis resembles a small eggplant, turned purple from blood otherwise contained within intact tissue. Luckily, most reported cases of penile fracture can be healed with proper medical care — surgery, drainage, a brief period of abstinence — and the afflicted can eventually return to the activity that broke the camel's back, as it were, in the first place. But healing takes time, which is important because time is human nature's worst enemy in certain situations, as Jeff Winkler, writing in The Awl, found out when things became hot and heavy a little too soon after the surgery:

"[T]he teeth-gritting and mattress-punching is clearly alarming her."