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Patient Education Center

Foamy Urine: What It Means and When to See a Doctor

Many people may have experienced going to the bathroom and noticing that their urine looks unusually foamy or bubbly. While it might be alarming at first, foamy urine is a relatively common occurrence. In most cases, it's nothing to worry about, but in some situations, it could be a sign of an underlying health issue. It's important to understand what causes foamy urine and what actions should be taken if it is noticed.

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What Causes Foamy Urine?

In most cases foamy urine is nothing to worry about, but in some situations, it could be a sign of an underlying health issue.

There are several reasons why urine might appear foamy:


When a person isn't drinking enough fluids, their urine becomes more concentrated. This can cause it to appear darker and foamier than usual. The foam is caused by the higher concentration of proteins and other compounds in the urine.

Rapid urination

If someone has a full bladder and urinates with a lot of force, the stream can create bubbles in the toilet bowl. This is a normal occurrence and not a cause for concern.

Person cleaning a toilet bowl with a green rag and disinfectant

Cleaning products

Sometimes, residual cleaning products in the toilet bowl can react with urine and create foam. This is not related to a person's health.

Kidney disease

In some cases, foamy urine can be a sign of kidney disease. When the kidneys are damaged, they can allow protein to leak into the urine, causing it to appear foamy. This condition, known as proteinuria, can be an early sign of kidney dysfunction.


High blood sugar levels can cause the kidneys to work harder, potentially leading to kidney damage and protein leakage into the urine. In fact, moderately increased albuminuria (microalbuminuria) is often one of the first signs of diabetic kidney disease.

Certain medications
Some medications, such as those used to treat hypertension (ACE inhibitors and ARBs), can cause proteinuria as a side effect.

Urinary tract infections

While not a common cause of foamy urine, UTIs can sometimes lead to excess protein in the urine due to inflammation.

Other Factors Affecting Urine Foam

Interestingly, the composition of urine itself can contribute to foam formation. A recent study published in the Clinical Journal of the American Society of Nephrology discussed how certain organic compounds called surfactants, which are naturally present in urine, can cause bubbling. These surfactants have both hydrophilic and hydrophobic ends, allowing them to trap pockets of air and create bubbles.

The researchers found 16 metabolites with surfactant properties in normal human urine, mostly bile salts and fatty acid esters. In some conditions, such as liver disease (cholestasis) or small intestinal bacterial overgrowth, these metabolites may be present in higher than usual amounts, potentially leading to foamy urine even in the absence of proteinuria.

When to See a Doctor About Foamy Urine

If a person notices foamy urine frequently, especially if it’s accompanied by other symptoms, it’s a good idea for them to see a doctor.

If a person notices foamy urine frequently, especially if it's accompanied by other symptoms like swelling in the legs or around the eyes, it's a good idea for them to see a doctor. The doctor can run some simple tests to check kidney function and rule out any underlying health issues.

The doctor will likely start with a urine dipstick test, which can detect the presence of protein in the urine. If the test comes back positive, they may recommend additional tests, such as a 24-hour urine collection, to get a more accurate measure of the amount of protein being excreted. In some cases, the doctor may also recommend imaging tests like an ultrasound or CT scan to get a better look at the kidneys and check for any structural issues.

What to Do About Foamy Urine

If foamy urine is caused by dehydration, the solution is simple: the person should drink more fluids! They should aim for at least 8 glasses of water per day, and more if exercising or spending time in hot weather.

If an underlying health condition is causing the foamy urine, treatment will depend on the specific issue. For example, if a person has diabetes, managing blood sugar levels through diet, exercise, and medication can help protect the kidneys and reduce protein leakage.

If kidney disease is the culprit, the doctor may recommend medications to help control blood pressure and slow the progression of the disease. In some cases, lifestyle changes like eating a low-sodium diet and getting regular exercise can also help.

It's important to note that while foamy urine can be a sign of kidney problems, not all cases of proteinuria indicate significant kidney damage. Isolated proteinuria (protein in the urine without other signs of kidney dysfunction) is often benign and may not require extensive evaluation. However, if proteinuria is persistent or associated with other concerning symptoms, further workup is warranted.

The Bottom Line

Foamy urine is often harmless, but it can sometimes be a sign of an underlying health issue like kidney disease or diabetes. If a person notices foamy urine frequently, especially if it's accompanied by other symptoms, it's a good idea for them to see their doctor for an evaluation. With prompt treatment, many of the conditions that cause foamy urine can be managed effectively.

People should pay attention to the clues their urine provides about their overall health, and it's always better to err on the side of caution when it comes to protecting the kidneys.


Northwestern Medicine®

Ghossein, Cybele, MD
"Foamy Urine: What's Normal, What's Not"
(No date.)

Medical News Today

Nall, Rachel, MSN, CRNA
"Why is my urine foamy?"
(Updated: May 31, 2023)

UPMC Health Beat (University of Pittsburgh Schools of the Health Sciences)

"When to Worry About Bubbly or Foamy Urine"
(Medically reviewed: March 11, 2021)


Rovin, Brad H., MD
"Assessment of urinary protein excretion and evaluation of isolated non-nephrotic proteinuria in adults"
(Topic last updated: August 8, 2022)

Clinical Journal of the American Society of Nephrology

Khitan, Zeid J., and Richard J. Glassock
"Foamy Urine: Is This a Sign of Kidney Disease?"
(November 2019)

This patient education article is reposted with permission from and adapted for our use.

All information is reviewed by a board-certified physician.

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