Urine Odor

The kidney and urinary systems produce urine to help the body eliminate liquid waste and balance electrolytes such as potassium and sodium.

Urine is mostly water and typically has little to no odor. However, urine odor can sometimes vary from sweet to foul depending on the foods and drinks we consume, medicines we take, infections, and other health conditions.

In most circumstances, the urine of healthy people will not have a strong odor. Urine with a pungent smell may mean that it is more concentrated, having higher-than-normal levels of waste.

This article will review urine odor symptoms, causes, treatments, diagnostic testing, and when to see a healthcare provider.

Urine Odor Symptoms

Depending on symptoms, odorous urine may include various smells, such as:

• Sweet: Usually due to high glucose levels—or diabetic ketoacidosis—in uncontrolled diabetes
• Ammonia: Typically due to a higher concentration of ammonia in the urine due to dehydration
• Musty: Often the result of liver disease or liver failure
• Foul-smelling: Usually associated with a urinary tract or bladder infection
  
• Maple syrup odor: A symptom of maple syrup urine disease, a rare genetic nervous system disease

Causes of Urine Odor

Brief or mild urine odor symptoms may not signify a more significant medical condition. However, there are many types of health conditions that can cause urine odor symptoms. Some urine odor causes are:

• Foods, such as asparagus, garlic, onions, or brussels sprouts
• Some medications, vitamins, or supplements
• Dehydration (from a concentrated build-up of more ammonia than normal)
• A bladder infection, kidney infection, or yeast infection (in which bacteria multiplies producing a foul smell)
• Uncontrolled diabetes, or ketonuria (caused by a buildup of ketones, the chemicals your body makes when you burn fat, instead of glucose for energy)
• Maple syrup disease (a rare metabolic disease that prevents the body from processing certain amino acids, causing them to build up in the blood and urine)
  
• Chronic renal failure (which can cause a strong urine ammonia odor from the breakdown of urea)
• Liver disease or liver failure
  

What Medications Can Cause Urine Odor?

Some medications and supplements may also cause changes in urine odor, such as:

• High doses of the B vitamins thiamin and choline
• Some antibiotics, especially a group called sulfonamides
• Some diabetes medications, such as DiaBeta (glyburide)
• Rheumatoid arthritis medications, such as one called Azulfidine (sulfasalazine)

How to Treat Urine Odor

Treatment for urine odor depends on its cause. For example, urine odor due to severe dehydration typically resolves once a person consumes an adequate amount of fluids. If a medication is causing urine odor symptoms, talk to your provider to ensure that the symptom is expected and not a sign of something more serious.

However, other, more serious health conditions, such as infections, liver disease, kidney disease, or diabetes, will require various treatments to manage the disease causing the odorous urine.

Talk to a healthcare provider if you are experiencing unusual or resistant urine odor symptoms. Diagnostic testing, such as a urinalysis, may be necessary to determine the cause and ensure there are no other unknown underlying medical conditions.

Complications and Risk Factors Associated With Urine Odor

Risk factors associated with urine odor are not due to the scent but the underlying cause of it. For example, chronic liver failure patients have significant medical complications such as portal hypertension and hepatic encephalopathy that have associated risk factors related to the disease.

However, unless you're allergic, foods such as asparagus, onions, and garlic are generally healthy and pose no additional health risks other than causing a mild urine smell.

Are There Tests to Diagnose the Cause of Urine Odor?

Your healthcare provider may start by collecting a past medical history and performing a physical exam.

Your provider may also want to do a urinalysis, a simple urine test examining a small sample of your urine. This test is noninvasive and requires that you provide urine in a clear container for analysis.

A urinalysis typically includes three parts, which are:

• A visual exam can check for color and clearness.
• A microscopic exam checks for things that do not belong in normal urine, such as red blood cells, white blood cells, or bacteria.
• A dipstick test can detect abnormal levels of substances such as protein, glucose, bilirubin, blood, or white blood cells.

Depending on the urinalysis results, your provider may also want to do blood work to check for other possible reasons for the change in urine odor. They may also order diagnostic imaging such as a computed tomography (CT) scan or magnetic resonance imaging (MRI) to see if there is another medical issue.

When to See a Healthcare Provider

You should see your healthcare provider if you’re experiencing a strong or persistent urine odor, especially if you have any other usual medical issues occurring. They may order a urinalysis and other diagnostic tests that can help to shed some light on what is causing the problem.

Summary

In most circumstances, the urine of healthy people will not have a strong odor. However, urine odor can vary from sweet to foul depending on various foods, medicines, infections, and other health conditions. 

Brief or mild urine odor symptoms can stem from certain foods, medications, vitamins, or dehydration. However, more severe health conditions may cause urine odor symptoms, such as an infection, ketonuria, liver disease or liver failure, and chronic renal (kidney) failure.

Risk factors associated with urine odor are not due to the smell but the underlying cause.

A Word From Verywell

Urine odor may be concerning. But the good news is that visiting your healthcare provider can help undercover the cause. If you or a loved one is experiencing odorous urine, see your healthcare provider to rule out any unknown underlying medication conditions that may be causing your symptoms.