Pronounced: high-drow nef-row-sis
Hydronephrosis occurs when urine builds up in the kidneys and cannot drain out to the bladder. The kidneys swell from the excess urine. The condition may affect one kidney or both. Hydronephrosis is not a disease itself, but rather a sign of another disease or condition affecting the kidneys. Swelling of the kidneys can lead to kidney damage.
This is a serious condition that requires care from your doctor. Most patients who have hydronephrosis will not know it until it has already damaged the kidney. Therefore, if you are at risk for this condition, it is important to be under the care of a physician.
Hydronephrosis is caused by two problems in the urinary system. A blockage may prevent urine from draining out of the kidneys. Or a condition called reflux may cause urine to flow back into the kidneys from the bladder.
Conditions that may cause hydronephrosis include:
The following factors increase your chances of developing hydronephrosis:
Hydronephrosis may or may not cause any symptoms. If symptoms occur, they may include:
Your doctor will ask about your symptoms and medical history, and perform a physical exam, which may involve examination of the pelvis or rectum to feel for blockages. You will likely be referred to a urologist and/or nephrologist for further diagnosis and treatment.
Tests may include:
Some causes of hydronephrosis resolve without treatment (such as pregnancy and kidney stones).
Treatment options include:
In general, the causes of hydronephrosis cannot be prevented. Prompt treatment of conditions that cause hydronephrosis reduces the risk of complications, such as kidney failure.
American Kidney Fund
American Urological Association
National Kidney Foundation
BC Children’s Hospital
BC Health Guide
The Kidney Foundation of Canada
Hydronephrosis. Mayo Foundation for Medical Education and Research website. Available at: http://www.mayoclinic.com/invoke.cfm?id=AN00829 . Accessed August 18, 2005.
Kasper DL, Braunwald E, Fauci A, Hauser S, Longo D, Jameson JL, eds. Harrison’s Principles of Internal Medicine . 16th ed. New York: McGraw Hill; 2005.
Kidney disease and kidney failure. National Kidney and Urologic Disease Information Clearinghouse website. Available at: http://kidney.niddk.nih.gov/kudiseases/topics/failure.asp . Accessed August 18, 2005.
Your child has hydronephrosis. National Kidney Foundation website. Available at: http://www.kidney.org/atoz/atozPrint.cfm?id=151# . Accessed August 24, 2005.
Last reviewed October 2012 by Adrienne Carmack, MD
Last Updated: 10/31/2012