Post-orgasmic illness syndrome (POIS) is a mostly male-based affliction that is incredibly rare. Immediately or soon after climaxing, it triggers a range of effects unrelated to the genitals, including confusion, the inability to speak, read, or write coherently, severe muscle pain throughout the body, severe fatigue, itchy eyes, feverishness, and influenza-like symptoms for up to a week.

This bizarre condition, first described in 2002, has no known cause and no known cure, and it’s genuinely debilitating. Very little is known about it, but a new article in the journal Sexual Medicine Reviews summarizes what researchers know about POIS so far.

The types and severity of the symptoms vary among men, but generally speaking, there appear to be two types of POIS: primary and secondary. The former is when POIS symptoms occur from their very first ejaculation, and the latter is one that develops later in life.

Either way, they occur during almost all orgasms involving ejaculate. Although there’s a tenuous link to premature ejaculation, the underlying mechanism is unknown.

The fact that there are only 50 described cases in medical literature doesn’t provide nearly enough detail to those hoping to find answers to this most cryptic of cases. Nevertheless, a few hypotheses have inevitably sprung up.

The most supported idea focuses on the man’s semen. Although it’s still circumstantial evidence at this time, some suggest that the patients are allergic to their own semen, or some component in it.

Another theory posits that the chemicals released during orgasm are being released in unusually high volumes.

Endorphins, for example, are well-known hormones produced by humans. They are opioids, and like other opioids, they inhibit pain and produce feelings of euphoria.

They turn up during orgasms too, but in men with POIS, they may be flooding the system somewhat. This means that when they fade away, the person enters an opioid withdrawal-like state, much in the way someone coming down from a heroin high would experience.

It’s recently been suggested that some women are affected by POIS, but at present, the only verified diagnoses have been in men. In the women affected, however, the condition is thought to be connected to the tissue in the lower genital tract, but any additional concrete details are still forthcoming.

Although experimental treatments are beginning to pop up, for now, the study – led by the Tulane University School of Medicine – concludes that much of what triggers POIS is a mystery.

“Further studies are warranted to investigate the prevalence, pathophysiology, and treatment of this debilitating condition,” they noted.

They acknowledge, as do its original discoverers, that most men that have it do not know it's a recognized condition. As a result, they refrain from seeking treatment.

[H/T: Forbes]