Medically Reviewed by Dan Brennan, MD on April 13, 2022
What You Eat or Drink

What You Eat or Drink


Asparagus might be the most common reason for stinky pee. The harmless odor is caused by a breakdown of asparagusic acid. Your genes affect whether you can smell these sulfur byproducts. If you can’t, that’s called asparagus anosmia. Your pee may also have a strong smell after you drink coffee, or eat fish, onions, or garlic.




Fluids help water down, or dilute, your pee. While there’s always waste in your urine, like ammonia, the smell is stronger if you’re dehydrated. That doesn’t mean you’re unhealthy. But a lack of fluids does raise your chances of getting kidney stones and urinary tract infections. That’s why it’s important to drink water when you’re thirsty. Fruits and vegetables can help hydrate you, too.

Urinary Tract Infections

Urinary Tract Infections


You may go to the bathroom a lot if you have a UTI. While you’re in there, you might get a whiff of something that doesn’t smell good. That’s because bacteria can build up in your urine and make it stink. Talk to your doctor if it hurts to pee and you have a fever. You may need to take antibiotics to get better.

Kidney Stones

Kidney Stones


These make your pee smell for a few reasons. They can stop or slow urine flow, leading to a buildup of salt and ammonia. They can also make infections more likely. Some stones are made from cystine, a substance with sulfur in it. If cystine is in your urine, it may smell like rotten eggs. Tell your doctor if you have a fever, blood in your pee, or if you’re in a lot of pain. You may need to get the stones taken out at a hospital.  

Uncontrolled Diabetes

Uncontrolled Diabetes


Your pee or breath may smell fruity if you don’t treat high blood sugar. The sweet smell is from ketonuria, or a buildup of ketones. Those are chemicals your body makes when you burn fat, instead of glucose, for energy. Tell your doctor right away if you vomit, have trouble breathing, or feel confused. You could have a serious condition called diabetic ketoacidosis. They’ll test your pee for ketones and help you manage your diabetes.

Maple Syrup Urine Disease

Maple Syrup Urine Disease


People born with this condition can’t break down certain amino acids. When these amino acids build up, their pee or earwax starts to smell sweet. If your baby has the disease, you may notice this syrupy odor a day or two after they’re born. They’ll need to follow a special diet. Your doctor can help you figure out ways to manage your child’s condition.

Sexually Transmitted Infections

Sexually Transmitted Infections


Some STIs can lead to a smelly discharge in males and females. You may notice the smell as the fluid mixes with your pee. You may not have other symptoms. Or your genitals may itch, and it might burn when you pee. Bacterial infections like chlamydia can be cured with antibiotics. You’ll need another kind of medicine for viral infections.

Vitamin Overload

Vitamin Overload


Your body gets rid of nutrients you don’t need through peeing. Extra vitamin B6 (pyridoxine) can give it a strong odor. Too much vitamin B1 (thiamine) can make your pee smell like fish. B vitamins can also make your pee look a bright greenish-yellow. Talk to a doctor about what vitamin doses are right for you.




Sulfa drugs can give your pee a bit of stench. That includes sulfonamide antibiotics. They’re commonly used to treat UTIs and other infections. Medicines for diabetes and rheumatoid arthritis also can affect the way your pee smells. If the stinky scent bothers you, tell your doctor about it. They might want to make sure nothing else is causing the odor.




Morning sickness may leave you dehydrated. And prenatal vitamins might change the way your pee smells. Pregnancy also raises your chances of urinary tract infections and ketonuria. You could just be super sensitive to scents. That’s called hyperosmia. Experts think hormones may change your perception of smells. And that means that even if your pee is the same, it may seem like the odor is weird or more intense.

Organ Failure

Organ Failure


Liver disease can make your pee and breath smell musty. The odor is caused by the buildup and release of toxins in your urine. If you have kidney failure, you may smell a lot of ammonia when you go to the bathroom.




Let your vagina clean itself. Washing inside of it could upset the balance of good and bad bacteria. That can lead to infections and discharge, which can smell bad when you pee. Health issues linked to douching include yeast infections, bacterial vaginosis, and pelvic inflammatory disease. There’s no need to erase your vagina’s natural odor. If you notice a new or strange scent, talk to your doctor. They can tell you if it’s normal.  

Poop Gets in Your Bladder

Poop Gets in Your Bladder


A fistula is an extra opening that forms between two organs. If you get one between your bladder and bowels, poop or gas may come out when you pee. You might get this kind of fistula if you have cancer or an inflammatory condition, like Crohn’s disease or diverticulitis. If you’re female, it may happen after you give birth or have a certain kind of operation. Surgery can fix fistulas. 




Some babies are born with a condition called tyrosinemia type 1. It means they don’t have the right enzyme to break down the amino acid tyrosine. Too much of this compound can give body fluids, like urine, a rotten odor. It may smell like cabbage. Tyrosinemia is treated with medicine and a low-tyrosine diet.  

Fish Odor Syndrome

Fish Odor Syndrome


Also called trimethylaminuria, this genetic condition can give your pee a fishy smell. It happens when your body can’t break down trimethylamine. You end up getting rid of the compound through your pee, sweat, breath, and other fluids. It doesn’t mean you’re unhealthy. But your doctor can help you manage the smell. They may give you antibiotics, special soap, or suggest eating certain foods.

Holding It for Too Long

Holding It for Too Long


Your urine might smell funky if it hangs out in your bladder for a while. That may also raise your chances of getting a UTI. This may happen more often in children who don’t pee when they feel the urge. That’s why it’s always a good idea to remind kids to take bathroom breaks.

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