Persistent sexual arousal syndrome. An allergy to cold temperatures. Music-induced seizures.
They are conditions that you may be hard-pressed to find in the medical literature. Bring them up in front of a physician, and in some cases you may get little more than a blank stare.
But they exist. And while such rare conditions are cocktail-party fodder for some, they can be a source of difficulty and shame for those who experience them firsthand.
The following pages feature some of the more unusual medical conditions that have received recent media attention.
Natalie Adler, 21, of Caulfield South, Melbourne, Australia, says she can sense the onset of her unusual condition -- and when she should start preparing for three days of darkness.
"The night before it sets in, my eyes get quite heavy and that is how I know it is coming," Adler told ABCNews.com.
Invariably, the next morning Adler finds herself unable to open her tightly shut eyes. The bouts generally last for about three days, after which she can open her eyes and once again see normally.
Adler said she has suffered from the condition for the last four years. Doctors, both in Australia and the United States, are baffled as to the exact cause -- or indeed, whether her condition is physical or psychological.
"We're not really sure of the diagnosis," said Catherine Mancuso, an orthoptist who coordinated Adler's treatment plans at The Royal Victorian Eye and Ear Hospital in Melbourne, Australia.
"There's nothing that would cause symptoms of a woman to close her eyes for three days, and open her eyes for three days," said Dr. Dean Cestari, a neuro-ophthalmologist at the Massachusetts Eye and Ear Infirmary in Boston.
Cestari believes that at least part of Adler's condition may be attributed to a psychological condition that has manifested itself in a physical way.
"It can be hard, because sometimes these patients come in with real experiences. They aren't making this up," said Cestari. "But the mind converted a conflict into a physical manifestation."
For now, Adler receives Botox treatments to the muscles surrounding her eyes. The injections often help her to keep her eyes open, but she said that the effectiveness of the treatments is starting to wane.
Now she is holding out hope for a more permanent solution, as well as a way to continue her day-to-day life despite the condition.
"In the beginning, I tried to ignore it but have now learnt to live with it," she said.
For those who have never experienced persistent sexual arousal syndrome, or PSAS, its symptoms may seem more like a godsend or a dirty joke than a debilitating condition.
However, for the women who experience PSAS -- which causes them to live perpetually at the brink of orgasm -- the condition is a nightmarish curse. And up until 2001, it was a curse that didn't even have a name.
"I thought I was alone in this," Heather Dearmon, a 34-year-old South Carolina woman who experiences PSAS, told ABC News' "Primetime." "And this is after seeing every kind of doctor imaginable -- gynecologist, psychologist, psychiatrist — you know, everything. And none had ever heard of anything."