Just as not taking in enough H20 can leave your pee extra yellow, it can also make it extra smelly, too.
When your body breaks down the protein you eat, a colorless compound called urea is formed, which is excreted through your urine, says urologist Mehran Movassaghi, M.D., of Movassaghi Urology in Santa Monica, Calif.
Water dilutes the urea, so if you’re not drinking enough of it, your pee will contain a more concentrated dose of urea—making your urine both a deeper yellow and giving it a heavier ammonia-like smell, he says. If you rehydrate, your pee will usually get lighter and less stinky.
Asparagus is notorious for making urine smell, um, different—but not everyone who eats the vegetable notices it. According to a new study in BMJ, the pee these people produce after an asparagus-heavy dinner—usually described as a sulphoric smell—may be just as stinky, but they may lack the genes able to smell it.
The culprit is a particular sulfur compound found only in asparagus. But the food isn’t the only one to cause a switch, Dr. Movassaghi says. Garlic—which also contains sulfur— and high protein diets can also change pee aroma, as well as fenugreek, Brussels sprouts and curry.
Coffee beans contain a compound called caffeol, which is released during roasting—giving coffee that delicious, drink-me-now aroma. But it’s insoluble in water, which means it remains intact as it runs through your system and out when you take a leak.
So if you drink enough coffee—especially if you’ve been skimping on water and you’re a little dehydrated—the caffeol will be more concentrated, says urologist S. Adam Ramin, M.D. of Urology Cancer Specialists in Los Angeles, Calif. And that can give your pee a slight coffee-like smell.
The smell is worse if you’re dehydrated, since you’ll also be dealing with that concentrated urea, which can amplify the aroma.
When an infection occurs anywhere in your urinary tract, bacteria can change the color and smell of your urine, says Dr. Movassaghi.
Usually, you’ll notice a very strong ammonia odor, or it can be slightly sweet. In the case of UTIs, the urine is often cloudy or bloody as well. Since the infections are usually caused by bacteria, an antibiotic from your doctor can wipe them out—and the resulting odor, although you may have a different smell in the meantime from the medication.
Some vitamins, medications and supplements have ingredients that can change pee smell, and sometimes the appearance as well. Anyone who’s taken a multivitamin—especially one that contains vitamin B—and peed neon yellow after can attest to that.
Medications like antibiotics can also cause your pee to smell, because those that contain penicillin are derived from mold. That can give your urine a yeasty or fungus-like funk, but it should dissipate once you run through your antibiotic course.
There are some sexually transmitted infections that are known to cause malodorous urine, Dr. Movassaghi says. These include trichomoniasis, chlamydia and gonorrhea.
The change occurs because the organisms responsible for the diseases trigger more production of ammonia, which the body tries to clear through the urinary system.
On its own, mildly smelly pee isn’t usually worth a urologist visit unless it seems to be persisting, says Dr. Ramin.
If it comes with other symptoms like cloudy or bloody urine, pain or burning when you pee, or fever or chills, you may want to make an appointment. These can signal doctor-worthy issues, like an infection or even urinary stones.