What to Know About Unusual Smell of Urine

Medically Reviewed by Poonam Sachdev on October 08, 2023
Written by Cheryl Whitten
3 min read

Urine normally has a slight smell, but some unusual and strong smells may also be noticed. Odd smells along with feeling sick, pain, or bloody urine are a sign you should see your doctor. 

Urine is mostly waste products and water and normally has a mild smell and a light yellow color. If you have more waste than water in your urine, it can smell more strongly. 

In most cases, a strong smell isn’t a sign of disease. It’s usually from your diet and medications, or it means you need to drink more water. Certain urine smells can be a sign of some conditions, but your doctor might not consider that to be the case unless you have other symptoms.

Your food, vitamins, and medications are the most common cause of a bad urine smell.

Foods. Some foods have compounds that naturally have a strong odor and can make your urine smell. These include:

Vitamins. B vitamins are water soluble, which means your body doesn’t store them, and whatever you don’t need is removed in your urine. B vitamins in your multivitamin are often the culprit of smelly urine.

Medications. Some medicines like antibiotics can make your urine stink. Some antibiotics are made from mold and can make your urine smell yeasty.

Drinking lots of water throughout the day can help with these smells and keep your urine clear.

One warning sign of diabetes or high blood sugar is urine that smells sweet or fruity. The sweetness comes from sugar in your urine and is a sign your body is trying to get rid of extra sugar in your blood. Some people say their pee smells like Cheerios, which might be a sweet smell that you should tell your doctor about. 

Fruity-smelling urine can be a sign of other diseases and complications.

Diabetic ketoacidosis. Ketoacidosis is a dangerous complication of diabetes that happens when ketones build up in your blood. It causes symptoms like fruity breath, sweet-smelling urine, excessive thirst, and tiredness.

Maple syrup urine disease. This rare, life-threatening genetic condition prevents the body from breaking down some amino acids. It affects babies and children. 

When these build up in your blood, a compound called a branched-chain alpha-keto acid shows up in your urine and makes it, along with your earwax, smell like maple syrup. The disease can cause other serious symptoms like seizures, sleepiness, irritability, and poor feeding.

Foods that convert to sulfur compounds in your body can make your urine smell rotten. This smell is commonly compared to rotten cabbage or rotten eggs and can come from eating asparagus, garlic, and onions. There are rare conditions that create a rotten smell, too.

Trimethylaminuria. In this condition, your body can’t break down a compound called trimethylamine. This chemical on its own smells like rotten eggs, rotting fish, or garbage. As trimethylamine collects in your body, your sweat, breath, and urine will smell rotten or fishy.

Tyrosinemia. There are 3 types of tyrosinemia, which cause problems breaking down the amino acid tyrosine. Byproducts build up and cause breath, sweat, and urine to smell like boiled cabbage.

Strong, ammonia-like urine is a sign that you’re a little dehydrated. Drinking more water can often help. Sometimes, ammonia is also a sign of:

Urinary tract infection. Also called a UTI, such an infection happens when you have bacteria in any part of your urinary system. It causes strong or sweet urine. Other UTI symptoms include:

Liver disease. A problem with your liver can make your skin and eyes yellow and your urine dark and smelly. It can also cause stomach pain, throwing up, and feeling sick. 

Kidney stones. Crystals made of waste products and minerals can build up in your kidneys and form hard stones, which can cause strong-smelling urine. You might also feel sick, have pain that comes and goes, and have bloody urine.

In most cases, a strong urine smell is caused by your food or is a sign that you need more fluids. If your urine smells sweet, you feel unwell, or you have other symptoms along with foul-smelling urine, though, talk to your doctor. Treatment for an unusual urine smell depends on the cause.