Will Rogers, that most philosophic of humorists, once said: "There are three kinds of men. The one that learns by reading. The few who learn by observation. The rest of them have to pee on the electric fence for themselves." We don't know if he was right or not, but we are certain that "reading" your pee can tell you a lot about your health.

Four to eight times a day you'll pass urine, a mix of more than 3,000 chemicals and water, to remove toxins, salts, nitrogen metabolites, excess nutrients and liquid from your body so that your metabolism, blood pressure and brain can function optimally. So here's your guide to "reading" your pee for signs of trouble:

Color changes: Well-hydrated pee is colorless or slightly yellow - unless you take a multivitamin (half of one in the morning and half in the evening). It's the vitamin B complex that makes for bright-yellow vitamin P! If your urine is darker, it means you need to drink more water. Aim for around 64 ounces a day (more if you sweat a lot). Some medications can temporarily make urine turn florescent green (the antidepressant amitriptyline) or blue (the diuretic triamterene).

Odor changes: Most of the time urine is odorless (unless you're in the subway in August), but diabetes can trigger a sweet smell, and a pungent odor might indicate kidney stones or an infection. And then there's asparagus; some people are genetically predisposed to have an enzyme that produces that post-asparagus aroma.