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Why does urine smell?
Urine can vary in color — and smell — based on the amount of waste products as well as fluids you take in over the course of the day.
However, there are some out-of-the-ordinary smells that may indicate you need to seek medical treatment. One such example is a sweet smell to the urine, which can indicate excess glucose (blood sugar) in the urine.
Another is the smell of ammonia, which has a strong, chemical-like smell. While urine that smells like ammonia isn’t always cause for concern, there are some instances where it can be.
Waste products in urine often have an odor, but urine is usually diluted enough that the waste products don’t smell. However, if the urine becomes more concentrated — meaning there is a greater amount of waste products in relation to fluids — the urine is more likely to smell like ammonia.
Urea is one of the waste products found in urine. It’s a byproduct of the breakdown of protein and can be broken down further to ammonia in certain situations. Therefore, many conditions that result in concentrated urine can cause urine that smells like ammonia.
Conditions that can cause a person’s urine to smell like ammonia include:
Stones in the bladder or kidneys can build up due to excess waste products in the bladder. Additional symptoms of bladder stones include:
- cloudy urine
- blood in the urine
- stomach pain
- dark urine
Bladder stones themselves can be caused by a variety of conditions. Learn more about bladder stones.
Not having enough fluid circulating in the body means the kidneys are more likely to hold onto water, yet release waste products. As a result, the urine may be more concentrated and smell like ammonia. If your urine is darker in color and you’re passing only small amounts of urine, you may be dehydrated. Learn more about dehydration.
Urinary tract infection (UTI)
A bladder infection or other infection impacting the urinary tract can lead to urine that smells like ammonia. Other symptoms associated with a UTI include:
- pain when urinating
- stomach pain
- feeling like you need to urinate often without producing a significant amount of urine
In most cases UTIs are caused by bacteria. Learn more about UTIs.
Sometimes urine smells like ammonia due to a unique combination of foods. This is not usually cause for concern unless it’s accompanied by other uncomfortable symptoms.
Occasionally having urine that smells like ammonia isn’t usually cause for concern. You may need to drink more water to dilute your urine. However, if your symptoms are accompanied by pain or potential signs of infection, such as a fever, then you should see a doctor.
The doctor will start by asking questions about your symptoms. These may include:
- How long has your urine smelled like ammonia?
- Are there times when your urine smells especially strong?
- Are you experiencing any other symptoms, such as blood in your urine, fever, back or flank pain, or pain when urinating?
Your doctor will use these responses to consider the next diagnostic tests. Sometimes, a doctor will perform an exam to check a man’s prostate for signs of enlargement that could be affecting urination. They may also ask for a urine test. The urine sample is sent to a laboratory and then tested for the presence of bacteria, blood, or pieces of a bladder or kidney stone or other waste components. Usually this test, along with a description of your symptoms, can help a doctor diagnose the cause for urine that smells like ammonia.
Your doctor may also order imaging studies where they test for abnormalities in the kidneys, bladder, or other areas that could be affecting the urine.
Could urine that smells like ammonia be a sign that I’m pregnant?
The composition of urine doesn’t change much with pregnancy and therefore shouldn’t smell like ammonia. However, periodic testing of urine is common and recommended during pregnancy to help identify any potential issues. For instance, increased sugar in the urine could indicate a risk for gestational diabetes. Ketones in the urine is a sign your body is not getting enough carbohydrates. An increased protein level would be a possible sign of a urinary tract infection or kidney damage. Some of these conditions present as urine that smells like ammonia, but this is not the norm with every pregnancy.Elaine K. Luo, MDAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.
If urine that smells like ammonia is caused by an underlying infection, your doctor may prescribe antibiotics. These can reduce the incidence and overgrowth of bacteria in the urinary tract.
You should also take steps to practice good bladder health, which can reduce the incidence of dehydration and the likelihood that you will get a UTI.
Examples include drinking at least six 8-ounce glasses of water a day. Drinking a glass of cranberry juice a day or adding lemon to your water changes the urine’s acidity. This could be beneficial to your bladder health if you experience a lot of infections.
Most cases of urine that smells like ammonia can be treated with fluids or antibiotic medications.
Ideally, your urine should be pale yellow to straw-colored. If it remains darker than usual for longer than 24 hours, see a doctor. You should also always seek treatment if you believe you may have an underlying infection or other medical concern.
Urine may smell like ammonia when it becomes concentrated with waste products. A variety of conditions can cause waste products to build up in urine, such as bladder stones, dehydration, and urinary tract infections. In most cases, urine that smells like ammonia can be treated with fluids or antibiotic medications.