Foamy urine can be caused by a fast stream or dehydration, but persistent foam can signal protein in the urine. See a doctor if it continues.
Common causes
- Fast urine stream.
- Dehydration.
- Protein in urine (proteinuria), from kidney disease.
- Diabetes or high blood pressure.
- Retrograde ejaculation.
Is it serious
A little foam occasionally is normal.
See a doctor
If foam is persistent, with swelling, fatigue, blood or changes in urination. A urine test checks protein.
Why urine foams
Foam is common when urine hits the toilet water quickly, especially with a strong stream, a full bladder or a concentrated sample (dehydration). Bubbles that vanish in a minute or two are usually not a concern.
Proteinuria
Persistent foam that looks like soap suds and stays can mean protein in the urine, a possible sign of kidney damage. The kidney’s filters (glomeruli) normally keep protein in the blood. Proteinuria is defined as more than 150 milligrams of protein in the urine per day.
Causes of protein in urine
- Diabetes.
- High blood pressure.
- Glomerulonephritis and other kidney diseases.
- Preeclampsia in pregnancy (with high blood pressure and swelling).
- Infection.
- Heavy exercise or fever, causing temporary protein.
- Multiple myeloma, in rare cases.
Other causes
- Retrograde ejaculation (semen in urine).
- Cleaning products in the toilet.
- Medications such as phenazopyridine.
Kidney disease numbers
The CDC estimates that about 1 in 7 US adults, or 35.5 million people, have chronic kidney disease, and most do not know it.
Tests
Urine dipstick, urine albumin to creatinine ratio (UACR), blood tests (creatinine, eGFR) and blood pressure checks. Adults with diabetes or high blood pressure should be screened yearly.
What to do
- Drink more water and observe whether foam improves.
- Keep blood pressure and blood sugar under control.
- Avoid NSAID overuse.
See a doctor if
Foamy urine persists for more than a few days to weeks, or comes with swelling in the legs, face or around the eyes, fatigue, blood in urine, high blood pressure or decreased urination.
Kidney disease facts
The CDC estimates that about 35.5 million American adults, or 14 percent, have chronic kidney disease, and as many as 9 in 10 with early disease do not know it. Persistent foam can mean protein (albumin) in urine, measured by the urine albumin to creatinine ratio: under 30 mg/g is normal, 30 to 300 is moderately increased and above 300 is severely increased. Blood tests estimate kidney filtering as the eGFR. Diabetes and high blood pressure are the leading causes of kidney disease.
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Other causes and steps
Dehydration, a forceful stream, a high protein meal or intense exercise can temporarily increase foam. Men with retrograde ejaculation, urinary infections and some medicines can have foamy urine. If foam is persistent, ask for a urinalysis and albumin test, control blood pressure and blood sugar, avoid frequent NSAID use and stay hydrated. See a doctor for swelling of the legs, face or around the eyes, blood in urine, fatigue or changes in urination.
Based on data from the CDC and the National Kidney Foundation
