Definition

Protein in urine — known as proteinuria (pro-tee-NU-ree-uh) — is excess protein found in a urine sample. Protein is one of the substances identified during a test to analyze the content of your urine (urinalysis).

Low levels of protein in urine are normal. Temporarily high levels of protein in urine aren't unusual either, particularly in younger people after exercise or during an illness.

Persistently high levels of protein in urine may be a sign of kidney disease.