The eyes may be a window into the soul, but the toilet bowl is a window into the body. You can learn a lot about what’s going on inside your body by examining what comes out of it.
In fact, it’s become pretty standard advice to keep an eye on what you leave behind when you pee, and to aim for a light lemonade color as a sign of optimal hydration.
The problem, other than the fact that you have to look into the toilet bowl, is that taking a glance at the color of your pee isn’t always as accurate at predicting true dehydration as, say, a blood test, according to research in the American Journal of Clinical Nutrition.
The study examined hydration tests among older adults and found that urine color can be changed by too many other things to accurately predict hydration.
The yellow color of urine comes from a chemical byproduct that results when your kidneys do their job of processing waste, explains Koushik Shaw, M.D., a urologist and founder of Austin Urology Institute in Texas. The more dehydrated you are, the more concentrated the urine becomes and the darker the color gets.
“A pale yellow color reflects a good balance between over- and underhydration,” he says.
There are times, though, when you don’t see pale yellow in the bowl, and dehydration has nothing to do with it. Believe it or not, pee can come in a whole rainbow of colors.
Case in point: Heather West, who works in a hospital lab, captured the spectrum of pee colors in this pretty sweet (and slightly disturbing!) photo.
Here’s what you should know when your pee doesn’t look like lemonade.
You probably ate beets, or maybe blackberries, or even rhubarb. Red or pink pee after eating beets is common enough that it’s even got its own name: beeturia.
Some of the compounds responsible for the color of these pretty foods are excreted in the urine after the kidneys do their processing. It should clear up by the next day, but if red pee lingers, Shaw says, it could be a sign of a bladder or kidney tumor.
If you haven’t recently eaten one of these foods, and especially if you notice any blood clots or other pieces of tissue in your pee, please go see a doctor. Both are extremely rare, Shaw adds, but underdiagnosed.
Just like your skin can turn orange if you eat too many carrots, so can your pee. Overdoing it means you’ve delivered yourself a heaping dose of beta-carotene, which is then excreted in urine.
The over-the-counter UTI treatment phenazopyridine (Pyridium) and the blood thinner warfarin can also result in orange pee.
The good news, Shaw says, is you know you’re taking these meds and a good doctor will give you the heads-up ahead of time to expect color changes so you don’t freak out.
If you see more of a neon or fluorescent orange, though, something could be up with your liver, Shaw says, especially if you notice a yellowish tint to the whites of your eyes.
A vibrant, fluorescent yellow in your bowl is probably linked to your vitamin stash. B vitamins, especially B12, result in this dramatic hue change.
It’s no cause for concern—except for the fact that you probably paid good money for those vitamins you just peed out! (Here are 9 Signs You’re Not Getting Enough B12.)
Even if you don’t notice that hallmark asparagus smell, the vegetable might change the color of your pee to a greenish tint, Shaw says.
In some rare instances, though, green urine could be a sign of a specific form of urinary tract infection called a proteus infection. The bug that causes it can also cause kidney stones, so if you still see green and you haven’t eaten asparagus, it’s time to get it checked out, he says.
A rare genetic condition called hypercalcemia, which involves having too much calcium in your bones, can result in blue urine, Shaw says. Yep, blue pee is possible. But probable?
“It’s so rare, I’ll probably never see a case in my lifetime,” he says.
Porphyrias are a rare class of disorders that typically involve sensitivity to light and can sometimes lead to brownish urine due to the way red blood cells are broken down in the bodies of people with the condition.
It’s likely another never-in-his-lifetime scenario, Shaw says, but if your brown pee is accompanied by abdominal pain, rashes, or seizures, it’s possible you have thegenetic condition.
As blood breaks down, it can appear more brownish, Shaw says, so brown pee could also be a sign of something serious, like a tumor. Or if you’re a huge rhubarb or fava bean fan, you might also notice cola-colored pee after you’ve eaten those foods.
Pee doesn’t have to be green to signal that an infection has reared its ugly head.
“Sometimes urine is more concentrated or darker with a UTI,” Shaw says—it’s why we’re often told to drink plenty of fluids when we have one.
But water alone might not get you out of the woods, especially if your urine becomes a cloudy white color, Shaw says.
“That could be kidney stones or a really bad infection,” he says. “You’re basically peeing out pus.” Please take those symptoms straight to the doctor.
Bottom line? You’d rather ask your doctor about it when it’s not a big deal than when it is.
“Healthy urine can range from clear to dark yellow, but if it’s any other color in the rainbow and hydration or diet doesn’t fix it,” Shaw says, “it’s best to get it checked.”