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.
Your kidneys filter waste products from your blood while retaining what your body needs — including proteins. However, some diseases and conditions allow proteins to pass through the filters of your kidneys, causing protein in urine.
If a urine test reveals protein in your urine, ask your doctor whether you need further testing. Because protein in urine can be temporary, your doctor might recommend a repeat test first thing in the morning or a few days later.
Your doctor might order other tests, such as a 24-hour urine collection, to determine if there is a cause for concern.
If you have diabetes, your doctor may check for small amounts of protein in urine — also known as microalbuminuria (my-kroh-al-byoo-min-U-ree-uh) — once or twice each year. Newly developing or increasing amounts of protein in your urine may be the earliest sign of diabetic kidney damage.
Show References
- What you should know about albuminuria (proteinuria). National Kidney Foundation. https://www.kidney.org/atoz/content/proteinuriawyska. Accessed Jan. 19, 2017.
- Protein in urine. American Kidney Fund. http://www.kidneyfund.org/kidney-disease/kidney-problems/protein-in-urine.html. Accessed Jan. 19, 2017.
- Proteinuria. Merck Manual Professional Version. http://www.merckmanuals.com/professional/genitourinary-disorders/symptoms-of-genitourinary-disorders/proteinuria. Accessed Jan. 19, 2017.
- Rovin BH. Assessment of urinary protein excretion and evaluation of isolated non-nephrotic proteinuria in adults. https://www.uptodate.com/contents/search. Accessed April 14, 2020.
- Albuminuria: Albumin in the urine. National Institute of Diabetes and Digestive and Kidney Diseases. https://www.niddk.nih.gov/health-information/kidney-disease/chronic-kidney-disease-ckd/tests-diagnosis/albuminuria-albumin-urine. Accessed Jan. 19, 2017.
- Somers MJ. Orthostatic (postural) proteinuria. https://www.uptodate.com/contents/search. Accessed April 14, 2020.
- Kelepouris E, et al. Overview of heavy proteinuria and the nephrotic syndrome. https://www.uptodate.com/contents/search. Accessed April 14, 2020.
- O'Connell TX. Proteinuria. In: Instant Work-Ups: A Clinical Guide to Medicine. 2nd ed. Philadelphia, Pa.: Elsevier; 2017. http://www.clinicalkey.com. Accessed Jan. 20, 2017.
Original article: https://www.mayoclinic.org/symptoms/protein-in-urine/basics/definition/sym-20050656