Foamy Urine: What It Means if You Have Bubbles in Your Pee

When it comes to your health, it’s normal to worry when something is a little different—say, when your pee color is a bit off. But what about when you have foamy urine, or it looks like it has bubbles in it?

A single layer of bubbles in your urine that dissipates quickly is normal, says Zeynep Gul, MD, a urologist and Assistant Professor of Urologic Surgery at Washington University School of Medicine. Heavier foam, on the other hand, may not be. “This is usually multiple layers and may not flush all the way,” says Dr. Gul.

Most of the time, foamy urine doesn’t mean anything and has no obvious cause. If it happens repeatedly, though, check it out with a doctor, as it could be a sign of anything from dehydration or an infection to kidney disease.

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1. Peeing fast and hard

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“Certainly, a strong stream can result in foamy urine because the water in the toilet becomes turbulent and will produce bubbles,” says Elizabeth Kavaler, MD, a double-board certified urologist and Medical Director of Total Urology Care of New York. 

While, in this case, bubbles in the toilet aren’t a cause for concern—the habit itself can lead to problems, explains Justin Houman MD, FACS, a board-certified urologist and Assistant Professor of Urology at Cedars-Sinai Medical Center. “When you urinate too quickly or forcefully, you put unnecessary pressure on your bladder and pelvic floor muscles,” he says. “Over time, this habit can lead to dysfunction, including incomplete bladder emptying and increased risk of urinary retention.”

Dr. Houman says it’s best to relax and allow your bladder to empty naturally, as this promotes better urinary health and reduces strain on the urethra and surrounding muscles.

2. Dehydration

“Dehydration can make urine appear foamy,” Dr. Houman says. “[This is] because concentrated urine has a higher level of dissolved proteins and waste products, which can create bubbles when it hits the toilet water.”

He says your urine will also likely be a darker yellow color than normal. When we’re dehydrated, our kidneys try to hold on to as much water as possible—skewing urine color from a lighter, hydrated yellow to a darker, concentrated pee. 

Dr. Houman adds that other bladder-related signs of dehydration include a strong urine odor and an increased risk of bladder irritation, which may lead to more frequent urination or discomfort. 

3. Bacteria in your urine

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Your bladder flushes out bacteria through urination by design. But excess bacteria in your urine can contribute to foamy pee, Dr. Houman explains. 

He says this excess bacteria is most often due to a urinary tract infection (UTI). “Bacteria can interact with proteins and other substances in the urine, creating bubbles or foam.” 

Other signs of a UTI include:

• Pain or burning when peeing
• Cloudy or reddish urine
• A frequent urge to urinate, even if your bladder is empty
• Lower abdominal pain
• Foul-smelling urine
• Flu-like symptoms, such as fever, nausea, and fatigue

“UTIs can result from poor hydration, incomplete bladder emptying, or conditions like benign prostatic hyperplasia (BPH) or urinary retention that predispose individuals to infections,” Dr. Houman explains. Even stress can make you more susceptible to a UTI. 

4. Protein in your urine

A more common cause of foamy urine is protein in the urine, says Elena Campbell, MD, a urologist with Ochsner Health Center in Baton Rouge. This is called proteinuria or albuminuria (albumin is the main protein in your blood).

Having protein in your blood is normal. Having protein in your urine is not. It means your kidneys aren’t working properly.

Healthy kidneys filter waste products out of the blood while keeping protein inside, where it performs functions like healing tissue and fighting infections. Protein in your urine can be a sign of kidney disease, which might also indicate you have diabetes or high blood pressure.

However, only about one-third of people who have foamy urine have detectable protein, and even then, it doesn’t necessarily mean anything is wrong, according to the Clinical Journal of the American Society of Nephrology.

5. Kidney disease

“When the kidneys lose function, protein can leak into the urine, causing persistent foaming,” Dr. Houman says. 

The only way to know for sure if you have protein in your urine is to have your healthcare provider do a urine test. They will put a dipstick into a sample of your urine. The dipstick will change color if it detects albumin, not unlike a pregnancy test.

“It takes two minutes to get results and get in-office,” says Dr. Gul.

One positive test isn’t anything to worry about, but three positive results in a span of three months could mean you have kidney disease, according to the National Institute of Diabetes and Digestive and Kidney Diseases.

6. Diabetes

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Diabetes can lead to foamy urine due to excess protein in the urine—particularly the protein albumin (causing albuminuria), Dr. Houman says. “This is often a sign of kidney damage (diabetic nephropathy).” Diabetic kidney disease, either from type 1 or type 2 diabetes, is the leading cause of kidney failure in the U.S., according to the National Kidney Foundation. 

Here’s why: Millions of tiny, specialized blood vessels in the kidneys filter out waste products from your blood through tiny holes—and those holes don’t allow larger protein molecules to exit the body. “High blood sugar levels, over time, can damage the kidney’s filtering system, allowing protein to leak into the urine,” Dr. Houman explains. And that protein leakage causes foamy urine. 

He says other symptoms that may accompany diabetic kidney damage include:

• Frequent urination
• Excessive thirst
• Fatigue
• Blurred vision
• Slow wound healing

But it’s important to know that early kidney disease usually doesn’t produce any symptoms. That’s why people with diabetes should have their urine monitored regularly and take steps to control their blood sugar levels, protecting their kidneys. 

7. High blood pressure

Like high blood sugar, consistently high blood pressure (hypertension) can damage the kidneys’ delicate filtration system, Dr. Houman says. The constant force of blood pushing through narrowed veins and arteries puts so much strain on the kidneys that they lose their ability to filter correctly.

He explains that this leads to protein leakage into the urine—proteinuria—which can create foamy urine. “This is often a sign of chronic kidney disease (CKD).” 

In fact—after diabetes—hypertension is the second leading cause of kidney disease. Dr. Houman adds that other symptoms of hypertension-related kidney disease can include:

• Swelling in the legs or face (edema)
• Fatigue
• Changes in urine output
• Difficulty concentrating

As with diabetes, the best way to prevent these problems is to keep blood pressure in the safe zone. Diet and exercise, as well as medications, are the best way to manage both hypertension and diabetes.

7. Medications

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Dr. Houman says certain drugs can contribute to foamy or bubbly urine if the medication impacts kidney function or your hydration status. 

Medications that may cause foamy urine include:

• Phenazopyridine: This is a pain medication used to treat UTI symptoms.
• Diuretics: Commonly used to treat high blood pressure, diuretics can sometimes lead to dehydration, causing concentrated, foamy urine. 
• NSAIDs (nonsteroidal anti-inflammatory drugs): NSAIDs, such as Advil or Aleve, can increase protein levels in your pee.
• Antibiotics: Antibiotics can sometimes affect urine protein levels, leading to foamy urine as a side effect.

Talk to your doctor if you’re taking medication and experiencing foamy urine (or any unexpected symptom, really). If your doctor determines a drug is the cause, they may adjust your medication or reassess your treatment plan. 

7. Semen residue

“For men, small amounts of semen remaining in the urethra after ejaculation can mix with urine and cause temporary bubbles,” Dr. Houman says. 

This is usually harmless. But if it’s a recurring issue, you should see your doctor to rule out any potential problems. 

When to see a doctor

Most of the time, foamy urine is nothing to worry about, but you should be vigilant if you have any risk factors for kidney disease. Foamy urine along with swollen legs and swelling around the eyes can be a sign of kidney damage. If you have these three symptoms together, get help immediately.

You should also see a doctor if you have pain with urinating, urinary incontinence, or blood in the urine, says Dr. Kavaler.

In most cases, foamy urine is nothing to worry about. If a culture is negative, but the symptom persists, your doctor may just ask you to return in a month, says Dr. Gul.

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