Why Is Pee Yellow?

Before you could speak, you could pee. Before you learned to write your own name, you could pee. (And if you grew up in a particularly snowy part of the world, you may have combined these skills.) Urination is a taboo subject, a daily miracle, an essential bodily function, and a complete mystery to most people who do it.

Let’s part the underpants-shaped veil surrounding urination information. Let’s learn about peeing.

What Is Peeing, and How Does It Work?

Peeing is one of the body’s astonishing waste-removal systems. Along with pooping and sweating, urination takes the leftovers from cellular processes like metabolism and respiration and carries them out to the anatomical curb. If for some reason any of these processes failed, the accumulated waste would do as garbage does, and make you very sick. 

Urination—also known as uresis, micturition, voiding, and going to see a man about a dog—is actually the finale of an epic physiological saga. Our story begins, as so many do, in the heart. Blood is pumped through renal arteries into the kidneys for filtration. After pulling out all the salts, potassium, and other chemicals the body doesn’t need, the kidneys send purified blood back into the heart. Everything that remains is pee. The newly mixed urine flows into long, skinny tubes called ureters, then into the bladder. As the bladder nears capacity, your brain gets a message that it’s time to go. As soon as you give the signal, your pee rushes from your bladder to your urethra to your genitals, and from there to the blinding light of the world outside your body.

TL; DR/VERDICT/SHORT ANSWER: Peeing is awesome and necessary. Also, kidneys.

Why Is My Pee Always Yellow? (And What If It Isn’t?)

Urine’s characteristic sunny hue comes primarily from a substance called urobilin. When your body is properly hydrated, the urobilin is diluted with plenty of water, and your pee is a nice, normal buttercup color. Amber or ale-colored urine is a reliable sign of dehydration, and clear pee is a signal that it’s time to put down the Nalgene. No matter what supermodels say, remember: It is possible to drink too much water.

And what if your urine isn’t yellow at all, but red, or blue, or even black? Well! Then you’ve got a riddle to solve.

Have you eaten a lot of borscht recently? You may be suffering from beeturia, which is the technical term for peeing red or pink after eating a lot of beets. I am not making this up. Ingesting enormous quantities of strawberries or rhubarb can produce the same effect.

Are you on a new medication? The pharmaceutical additive methylene blue can turn your urine a startling blue or green. Eating too much asparagus or food coloring (I’m looking at you, festive green beer) can also cause verdant pee. Orange urine may be medication- or vitamin-related, or you may have forgotten that carrot feast last night. There’s a fruit or vegetable to blame for nearly every color of the urine rainbow.

NOTE: If your pee is dark brown, reddish (and not in a charming, beet-y way), or black, get yourself to a doctor. Urine color has been a diagnostic tool since Greco-Roman times. Physicians and self-appointed “piss prophets” divined a visitor’s health, illness, or destiny by looking at, sniffing, and even tasting his or her urine. Your doctor will probably not take it that far. 

TL; DR/VERDICT/SHORT ANSWER: A) urobilin! B) Lay off the beets! C) If your diet is beet-free, see a doctor.

Is It True That You Can Drink Your Urine?

The piss prophets probably gave this answer away, but yes, technically, you can, since urine is generally bacteria-free and nontoxic. The real question is “Why would you?”

Some people have their reasons. (You’d have to, right?) In a life-or-death situation, with no potable water, imbibing your own wee may keep you alive longer, but don’t make it a habit. Remember the garbage metaphor? Because urine is a waste product, each cycle through your body adds a new batch of toxins, so after a while, drinking the stuff would do you more harm than good.

Other pee drinkers believe their habit lengthens their lifespan. Practitioners of “urotherapy” claim that consuming your own urine can cure acne, weight problems, and even cancer. The American Cancer Society does not agree.

TL; DR/VERDICT/SHORT ANSWER: Sure, you can. You can also hit yourself with a hammer or chew gum that’s lost its flavor. You are the captain of your own destiny. Choose wisely.

Should I Pee On This Jellyfish Sting? What About This Patch of Athlete’s Foot?

Only if you want to make it worse and/or spend the day smelling like pee for no reason. Urine may be sterile, but it does not have magical healing properties. It’s as effective as clean water (which is fairly ineffective) for treating athlete’s foot, and can fire up the jellyfish stingers that burned your skin in the first place.

TL; DR/VERDICT/SHORT ANSWER: No, and no. 

Why Do We Call It Pee?

Urine is the oldest word for our personal waters in the English language, originating from the Old Norse ur, meaning “drizzling rain.” Piss, that delightful onomatopoetic term, came next. “Piss,” with all its coarseness and icky connotations, was euphemistically abbreviated to the letter “pee” by squeamish parents in the late 18th century.

TL; DR/VERDICT/SHORT ANSWER: Because we’re afraid of death, decay, and talking about our bodies.