Protein in urine — also called proteinuria (pro-tee-NU-ree-uh) — is an excess of bloodborne proteins in urine. Protein is one of the substances measured in a lab test to analyze the contents of urine (urinalysis).

The term "proteinuria" is sometimes used interchangeably with the term "albuminuria," but these terms have somewhat different meanings. Albumin (al-BYOO-min) is the most common type of protein circulating in blood. Some urine tests only detect an excess of albumin in urine. Excess albumin in urine is called albuminuria (al-BYOO-mih-NU-ree-uh). Proteinuria refers to an excess of multiple blood proteins in urine.

Low levels of protein in urine are typical. 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.

From Mayo Clinic to your inbox

Sign up for free and stay up to date on research advancements, health tips, current health topics, and expertise on managing health. Click here for an email preview.

To provide you with the most relevant and helpful information, and understand which information is beneficial, we may combine your email and website usage information with other information we have about you. If you are a Mayo Clinic patient, this could include protected health information. If we combine this information with your protected health information, we will treat all of that information as protected health information and will only use or disclose that information as set forth in our notice of privacy practices. You may opt-out of email communications at any time by clicking on the unsubscribe link in the e-mail.

May 05, 2022