Why might someone experience frothy urine and how is it diagnosed?

Reviewed by Yoshinori Abe, MD

Internal Medicine

Frothy or foamy urine is often caused by excess protein in the urine, a condition known as proteinuria. This can be an early warning sign of kidney problems, since healthy kidneys typically prevent large amounts of protein from leaking into urine. Diagnosis usually starts with a simple urine test to measure protein levels, followed by blood tests or imaging if needed to assess kidney function.

Because foamy urine can point to conditions ranging from mild dehydration to more serious kidney issues, it's important not to guess. Taking a free, instant, online symptom check can help you understand what your symptoms may mean and guide you on the best next steps—whether that's monitoring at home or seeing a doctor promptly.

Reviewed for medical accuracy: 07/15/2026

Quick answers

Frequently Asked Questions

4 answers

The most common questions people search after this page

Concerned about your symptoms?

Start a symptom check

Explanation

Frothy urine can happen when there is too much protein in the urine, which is sometimes a sign of kidney issues. When the kidneys are not working properly, they might let proteins like albumin leak into the urine. This can cause the urine to become frothy or bubbly.

Diagnosis

Urine Tests: To find out why urine is frothy, doctors often start with a urine test. This test checks how much protein is in the urine.
Further Tests: If the urine test shows high protein levels, more tests might be needed to understand why the kidneys are letting protein through.

Studies have shown that frothy urine is often linked to kidney conditions like nephrotic syndrome. This condition involves a lot of protein in the urine and can cause swelling in different parts of the body. If you notice frothy urine regularly, you can use Ubie's free AI-powered symptom checker to help understand your symptoms before talking to a healthcare provider to find out the cause and get the right treatment.

(References)

Kang KK, Choi JR, Song JY, Han SW, Park SH, Yoo WS, et al. (2012). Clinical significance of subjective foamy urine. Chonnam medical journal, 23323222.
Dantas M, Barros Silva GE, & Moysés-Neto M. (2013). Foamy urine in nephrotic syndrome. Clinical kidney journal, 26064498.
Diskin CJ, Stokes TJ, Dansby LM, Carter TB, & Radcliff L. (2000). Surface tension, proteinuria, and the urine bubbles of .... Lancet (London, England), 10752713.

Tell your friends about us.

We would love to help them too.

For First Time Users

What is Ubie’s Doctor’s Note?

We provide a database of explanations from real doctors on a range of medical topics. Get started by exploring our library of questions and topics you want to learn more about.

Was this page helpful?

Purpose and positioning of servicesUbie Doctor's Note is a service for informational purposes. The provision of information by physicians, medical professionals, etc. is not a medical treatment. If medical treatment is required, please consult your doctor or medical institution. We strive to provide reliable and accurate information, but we do not guarantee the completeness of the content. If you find any errors in the information, please contact us.