Bubbles in urine are usually caused by a fast stream, but persistent foam can signal protein in the urine. See a doctor if it keeps happening.
Common reason
Bubbles are usually caused by urine hitting the toilet water with force, especially with a full bladder. Dehydrated, concentrated urine can foam more.
Medical causes
Persistent foam can signal protein in the urine (proteinuria), from kidney disease, diabetes or high blood pressure.
Other causes
- Urinary tract infection.
- Retrograde ejaculation.
- Fistula (rare).
What to do
Drink water. If foam is frequent, ask your doctor for a urine test.
See a doctor if
Foam persists with swelling in the feet, face or eyes, fatigue, or blood in urine.
Testing
Urine albumin-to-creatinine ratio.
Common reason
Bubbles in urine are often just a result of the urine stream striking the toilet water at force, which traps air and creates foam. A strong stream from a full bladder, and urinating quickly, makes foam that dissipates within a minute or so. Concentrated urine from dehydration may foam more. Toilet cleaners can also create bubbles.
Medical causes
Foam that lingers and happens often may be due to protein in the urine (proteinuria), which makes urine behave like soapy water. This can be an early sign of kidney problems.
- Diabetic kidney disease.
- High blood pressure damage.
- Glomerular diseases such as IgA nephropathy.
- Preeclampsia in pregnancy.
- Lupus, amyloidosis and multiple myeloma.
Chronic kidney disease affects about 14% of US adults, or 35 million people, and about 9 in 10 do not know it.
Other causes
- Dehydration.
- Urinary tract infection, which can produce cloudy urine, odor and bubbles.
- Retrograde ejaculation, causing cloudy, foamy urine in men after sex.
- Strenuous exercise.
- A fistula between the bladder and bowel, which causes air in the urine (pneumaturia).
- High-protein diets or creatine supplements, which may temporarily raise protein levels.
What to do
- Drink more water and see if the foam goes away.
- Keep a short record of how often it occurs.
- Check blood pressure and blood sugar if you have not recently.
- Do not take large doses of NSAIDs.
See a doctor if
Foamy urine persists for more than a week, appears most times you urinate, or comes with puffiness around eyes, swollen feet, fatigue, blood in urine, pain, frequent urination, nausea or weight changes.
Testing
A dipstick urine test shows protein. A urine albumin-to-creatinine ratio over 30 mg/g shows kidney damage. Doctors also check blood tests for creatinine and estimated glomerular filtration rate (eGFR), and may repeat tests, since one-time results can be temporary. Early treatment with blood pressure control and medicines such as ACE inhibitors, ARBs and SGLT2 inhibitors can slow kidney disease.
Proteinuria and dehydration data
Foamy urine usually comes from a fast stream hitting the water. Concentrated urine from dehydration can also look foamy. Persistent foamy urine may signal proteinuria, where more than 150 mg of protein is lost per day, and it is a sign of kidney damage that is linked to diabetes, high blood pressure and glomerular diseases. About 1 in 7 US adults, or 14 percent, are estimated to have chronic kidney disease, and early stages usually have no symptoms. A doctor can order a urinalysis and a urine albumin to creatinine ratio test. Urinary tract infections, kidney stones, some medicines and eating a lot of protein may add to foaming. Toilet cleaner residue can cause bubbles in the bowl, so check with a fresh clean toilet and a clean cup. Drinking enough water is advised unless a doctor says otherwise. Seek medical attention if swelling, fatigue, blood in urine or ongoing foam occur.
Based on data from the CDC and the National Kidney Foundation
