A sulfur or rotten-egg smell in your urine is most commonly caused by harmless dietary factors, supplements, or dehydration. However, if the smell is persistent or accompanied by other physical symptoms, it could signal an underlying medical issue.
Healthy urine should have a very mild, sometimes slightly nutty or almost odorless scent. Unhealthy urine often has a distinctly pungent, foul, or sweet odor. The specific smell can help identify different underlying health issues:
If it smells like sulfur or rotten eggs, it could be natural gas. Any time you smell gas or suspect a leak, leave the area immediately. Then, once in a safe spot, call 911 and 1-888-482-4950 to report the odor.
Your pee smells like eggs because sulfur compounds from your diet or metabolic waste are being filtered by your kidneys. While often harmless, it can sometimes indicate an underlying infection.
Liver disease can compromise the organ's ability to filter toxins, causing metabolic byproducts to build up and be excreted in waste. This commonly results in musty, stale, or sweet-smelling urine, as well as urine that is unusually dark in color.
The four primary warning signs of a failing liver are:
A UTI most commonly gives urine a strong, foul, or ammonia-like odor. Bacteria breaking down urea create this pungent smell. In some cases, it can also smell sweet, sulfuric (like rotten eggs), or generally foul.
A sulfur or rotten-egg smell in your urine is most commonly caused by harmless dietary factors, supplements, or dehydration. However, if the smell is persistent or accompanied by other physical symptoms, it could signal an underlying medical issue.
Diabetes urine typically smells sweet, fruity, or like sugary cereals (like Sugar Smacks or Cocoa Puffs). This happens when your kidneys are working to flush out excess glucose (sugar) that the body cannot process.
Urinary tract infections (UTI)
One of the reasons stale urine smells so bad is that bacteria start breaking down the ammonia it contains. With a bladder infection, that process takes place inside your body, which can lead to smelly urine. Many people, especially women, have experienced a UTI.
A sulfur or rotten egg smell (often hydrogen sulfide) can indicate several medical conditions depending on where the odor is detected—breath, stool, or skin. Common causes include gastrointestinal issues like SIBO (Small Intestinal Bacterial Overgrowth) or high-protein diets, metabolic disorders like TMAU or hypermethioninemia, and in serious cases, liver failure.
The characteristic "old age smell" is scientifically known as nonenal (or 2-nonenal). It is a chemical compound produced when the skin's natural oils and fatty acids break down and oxidize as we age.
After Sodom and Gomorrah's destruction, sulfur became the “smell” of divine punishment. For instance, should Israel rebel against the covenant, their land will become “burned out with brimstone and salt” (Deut. 29:23). Isaiah depicts God's punishment as “the breath of the LORD, like a stream of sulfur” (Isa.
"Bad urine symptoms" usually indicate an infection or underlying condition. Common indicators include a burning sensation when peeing, a frequent or urgent need to go, pelvic pressure, or urine that is cloudy, bloody, or has a strong, foul odor.
Smelly urine is most commonly caused by dehydration, which makes your urine more concentrated. Drinking plenty of fluids will help dilute the urine and reduce the odor.
Smelly urine is most often caused by a urinary tract infection (UTI), a kidney infection, or uncontrolled diabetes. The specific smell can help pinpoint the underlying issue:
When your body is in ketosis, urine usually smells fruity, sweet, or similar to nail polish remover. This is caused by acetone, a type of ketone your body produces when burning fat instead of carbs. Additionally, a diet high in protein may sometimes cause a sharper, ammonia-like (or kitty litter) scent.
Dehydration pee typically smells highly concentrated, pungent, or like ammonia. Because you are not drinking enough water, waste products (like urea) are not properly diluted, resulting in a stronger odor and a darker yellow or amber color.
Autoantibody testing can detect early stages of type 1 diabetes, which can be treated before symptoms and serious complications appear. You may have your urine tested for ketones. Ketones are produced when your body burns fat for energy. Having ketones in your urine indicates you have type 1 diabetes instead of type 2.
The body converts a specific acid found in asparagus into a sulfur compound, resulting in pungent smelly urine. Other cruciferous veggies, like Brussels sprouts, can cause the same issue. Spices like cumin and sulfur-containing veggies like onion and garlic also change the scent of your urine.
Foetor hepaticus is a feature of severe liver disease; a sweet and musty smell both on the breath and in urine.
Pure, elemental sulfur is actually odorless and tasteless. However, when sulfur binds with other elements to form compounds, it produces highly distinctive and often unpleasant odors:
Here are the 5 most common warning signs of a urinary tract infection (UTI):
The fastest way to feel better is by taking an antibiotic to get rid of the bacteria causing your infection. If an in-person visit isn't an option, there are telehealth services available that allow you to set up a virtual appointment. Check out GoodRx Care for treatment of UTIs and many other medical conditions.
Several conditions share symptoms with urinary tract infections (UTIs)—such as burning, urgency, or pelvic pressure—but require entirely different treatments. Common culprits that mimic a UTI include: