Foamy urine: when bubbles mean protein

Dr. Joan J. Morales Lappot, MD
3 min read · Leer en español

In briefA few bubbles in the toilet are usually nothing. Foam that is thick and lasts, every time, can be a sign of protein in the urine.

Normal reasons for bubbles

• A strong or fast urine stream
• Concentrated urine when you are a little dehydrated
• Cleaning products in the toilet bowl

When foam may mean protein

Protein changes the surface tension of urine, a bit like egg whites being whipped. Foam that looks like the head on a beer, stays for several minutes and appears day after day deserves a test, especially if you also have swelling of the legs or around the eyes.

Who should pay closer attention

• People with diabetes or high blood pressure
• People with a family history of kidney disease
• People with lupus or other autoimmune conditions
• Anyone with new swelling or weight gain from fluid

The test that answers it

A urine albumin-to-creatinine ratio (UACR) measures protein accurately from a single sample. If it is normal, you can stop worrying about the bubbles. If it is high, we look for the cause and start protecting your kidneys.