Pee: A Girl's Guide to Plumbing

Your urine may be 95 percent water, but it can reveal whether you're pregnant, have diabetes, are taking painkillers, or even ate asparagus for lunch. It contains an awe-inspiring number of elements, including proteins, enzymes, minerals, hormones, electrolytes, and vitamins. Researchers say that someday urine may help doctors diagnose cancer.

The system of organs that manufactures your pee is equally remarkable -- until something goes wrong. More than half of all women suffer from incontinence, compared with a mere 14 percent of men, according to one large study. And you're also more likely to suffer infections and other pee-related problems than your guy (at least until middle age, when men's prostate problems start to swell). Adding insult to ­injury, you can't even pee standing up.

On history's stage, pee has had some pretty wacky roles. The Aztecs cleaned wounds with it and ancient Romans used it to whiten their teeth. Some World War I soldiers used pee-soaked cloths as gas masks, and more recently the U.S. military developed dried meals that can be rehydrated with urine. The practice of ingesting or applying the stuff, known as urine therapy, purportedly wards off disease, though peeing on a jellyfish sting probably won't stop the pain. Read our guide and you'll come away with a whole new appreciation for your urinary system.