The guy who brandishes an iron-clad erection for hours on end might seem like a dream come true, but as the evening progresses and the pumped up pumper doesn’t seem to be going anywhere but up, the dream can gradually turn to a nightmare. The condition characterized by an erect penis that doesn’t return to a flaccid state within four hours despite a lack of both physical and psychological stimulation is known as priapism.

If left untreated, this type of erectile dysfunction could have serious consequences, including thrombosis, which is clotting of the blood trapped in the penis. Damage to penile blood vessels—or, in serious cases, gangrene, which could require the removal of the penis—are also possibilities. Thus the origin of priapism’s namesake—the syndrome was coined after the Greek god Priapus, who was punished by other gods for attempting to rape a goddess and was given a huge—but useless—set of wooden genitals.

Males of all ages—including infants—can develop priapism, but it usually hits those between the ages of 5 to 10 years and 20 to 50 years. Priapism is brought on by a variety of causes. Medical conditions such as leukemia (cancer of the blood) and sickle-cell disease can be culprits. Medications such as antidepressants and antipsychotics—as well as illegal drugs—can lead to the phallic malady. While somewhat remote, the syndrome has also been linked to bites from black widows and the Brazilian wandering spider.

There are two categories of priapism listed in medical journals: low-flow and high-flow. Low-flow priapism is the result of blood being trapped in the erection chambers. This most often occurs in otherwise healthy men without a known cause, but can also affect men with sickle-cell disease, malaria or leukemia.

High-flow priapism is rarer than low-flow and for the most part is less painful. The cause can be a ruptured artery from an injury to the penis or the perineum (fleshy area between the anus and the scrotum). When these areas are damaged, blood in the penis doesn’t circulate normally, which causes an irregular erection.

To correct priapism, the attending physician will likely release blood from the corpus cavernosa section of the penis. If this fails, intra-cavernosal injections of phenylephrine are used.

Depending on one’s party drug of choice, dabbling in illicit chemicals or in some cases alcoholic beverages can come with the unwanted side effect of a perpetual penis. Cocaine is one such drug and has produced what at first seems like a godsend of sexual stamina when applied directly to the penis. When the hard-on far outlasts the buzz of the blow, however, the fun is pretty much over.