Why Your Urine Smells Bad: Understanding the Causes

Brief Overview of Urine Composition and Normal Odor

The kidneys filter blood to remove waste products from the body in urine (pee). Human urine is 95% water. The remaining 5% is waste products such as urea, ammonia,  creatinine, and uric acid, along with excess electrolytes like sodium, potassium, calcium, and chloride.

Normal urine is yellowish in color (it can range from clear to pale yellow). Fresh urine is typically odorless but may have a mild smell based on diet. 

Signs That Your Urine Odor May Not Be Normal

Three changes that can occur in urine that might indicate that your urine is not normal include:

• Changes in color (darker yellow, orange, pink, red, or dark brown)

• Changes in urine smell (sulfur smell, fishy smell, or sweet-smelling urine)

• Changes in appearance (foaming, frothing, cloudy urine, blood in urine)

Some of these changes are temporary and harmless, while others may indicate a more serious medical condition.

What Can Cause Foul-Smelling Urine?

Dehydration 

Not drinking enough water is a common cause of abnormal urine odor. When you’re dehydrated, your body tries to retain as much water as possible, resulting in concentrated urine. Consequently, the natural waste product ammonia is less diluted and causes a more intense smell. 

Dietary Influences

Certain foods can make your pee smell bad. For example, eating asparagus can give your urine a sulfur-like smell because of a substance called asparagusic acid. Other foods that can give your pee a stronger smell, including pee that smells like ammonia or sulfur, include:

• Seafood

• Onions

• Garlic

• Brussels sprouts

• Cauliflower 

• Cabbage

• Coriander

• Cumin

• Coffee

• Alcohol

Health Conditions

Certain medical conditions can cause strong-smelling urine, for example:

• Urinary tract infections (UTIs) (ammonia smell)

• Kidney stones and other kidney diseases

• Bladder infection (cystitis)

• Kidney infection (pyelonephritis)

• Prostate infection

• Yeast infections such as bacterial vaginosis 

• Sexually transmitted infections such as chlamydia

• Liver disease

• High blood sugar or uncontrolled diabetes (sweet-smelling urine)

• Diabetic ketoacidosis (fruity-smelling urine)

• Menopause

• Fistula (abnormal connection between the gastrointestinal tract and bladder)

• Metabolic disorders

• Trimethylaminuria (fishy-smelling urine)

• Phenylketonuria (musty odor)

• Maple syrup urine disease (sweet smell)

Medications and Supplements

Taking medications and dietary supplements can make your pee smell stronger. For example, sulfonamide antibiotics, diabetes medication, phenazopyridine, medicines used to treat rheumatoid arthritis, and B vitamin complexes such as thiamine and choline.

Urine Odor and Early Pregnancy

There can be changes in the smell of your urine if you’re pregnant due to:

• Hormonal changes, especially during early pregnancy

• Dehydration due to lack of sufficient water intake

• Use of supplements such as prenatal vitamins

• Heightened sense of smell during pregnancy

Symptoms to Watch For

Other Symptoms Accompanying Foul Smelling Urine

There’s usually a simple explanation for urine that smells a little different. In most cases, the smell disappears within a day or two. You don’t have to worry if you have smelly urine, especially if it isn’t accompanied by any other symptoms.

But if the foul smell of urine persists and you have additional symptoms, you should see your healthcare provider. Symptoms you should not ignore include:

• Cloudy urine 

• Blood in urine

• Pain or burning sensation with urination

• Frequency or urgency of urination

• Vaginal or penile discharge

• Abdominal pain

• Back or flank pain

• Fever, chills, nausea, and other signs of infection

Remedies and Solutions: How to Improve Urine Odor

It’s important to have unusually smelling pees, such as urine with a fish odor, evaluated by a healthcare professional. If your doctor has ruled out underlying health conditions, the following tips may help to prevent smelly urine:

• Drink enough fluids. The goal should be to drink plenty of water to stay hydrated. Avoid fizzy drinks, sugary beverages, coffee, and alcohol.

• Avoid eating foods such as asparagus and garlic that contain chemicals that can give you smelly pee.

• Avoid taking dietary supplements without your doctor’s approval. Certain supplements like vitamin B6 can change the smell of your urine.

• Maintain good personal hygiene in the genital area. 

Frequently Asked Questions

What causes urine to smell very strongly?

Strong-smelling urine can be the result of dehydration, certain foods, medical conditions, or medications.

How to get rid of strong urine odor?

It’s important to see your doctor to find out the cause of the strong urine odor. If your doctor has ruled out underlying health problems, drinking plenty of water can help you avoid dehydration and prevent smelly urine.

What is the strong smell of UTI?

A urinary tract infection (UTI) can make urine smell like ammonia due to the presence of bacteria in the urine. Check out our blog: How to Get Rid of a UTI in 24 Hours.

What does urine smell like in early pregnancy?

Early pregnancy is linked to an increased risk of urinary tract infections, which can cause ammonia-smelling urine. Check out 5 Effective Ways to Cure a UTI.