Hydronephrosis is swelling of one kidney due to a backup of urine. This problem may occur in one kidney.
Hydronephrosis (kidney swelling) occurs as the result of a disease. It is not a disease itself. Problems that may lead to hydronephrosis include:
- Blockage of a ureter due to scarring caused by prior infections, surgeries, or radiation treatments
- Blockge from an enlarged uterus during pregnancy
- Birth defects of the urinary system
- Back flow of urine from bladder to kidney, called reflux
- Kidney stones
- Cancers or tumors that occur in the pelvis or abdomen
- Problems with the nerves that supply the bladder
The blockage and swelling of the kidney may occur suddenly or may develop slowly.
Hydronephrosis in one kidney occurs in about 1 in 100 people.
Treatment depends on the cause of the kidney swelling. Treatment may include:
- Placing a stent (tube) through the bladder and ureter to allow urine flow in the kidney and bladder
- Placing a tube into the kidney through the skin, to allow the blocked urine to drain out of the body into a drainage bag
- Antibiotics for infections
- Surgery to correct the blockage or reflux
- Removal of any stone that is causing blockage
People who have only one kidney, who have immune system disorders such as diabetes or HIV, or who have had a transplant will need treatment right away.
People who have long-term hydronephrosis may need antibiotics to reduce the risk of urinary tract infections.
Loss of kidney function may occur if the condition is left untreated.
If hydronephrosis is left untreated, the affected kidney may be permanently damaged. Kidney failure is rare if the other kidney is working normally. However, kidney failure will occur if there is only one functioning kidney.
When to Contact a Medical Professional
Call your health care provider if you have ongoing or severe flank pain, or fever, or if you think you may have hydronephrosis.
Prevention of the disorders that cause this condition will prevent it from occurring.
Hydronephrosis; Chronic hydronephrosis; Acute hydronephrosis; Urinary obstruction; Unilateral hydronephrosis; Nephrolithiasis - hydronephrosis; Kidney stone - hydronephrosis; Renal calculi - hydronephrosis; Ureteral calculi - hydronephrosis; Vesicoureteral reflux - hydronephrosis; Obstructive uropathy - hydronephrosis
Frøkiaer J. Urinary tract obstruction. In: Skorecki K, Chertow GM, Marsden PA, Taal MW, Yu ASL, eds. Brenner and Rector's The Kidney. 10th ed. Philadelphia, PA: Elsevier; 2016:chap 38.
Zeidel ML. Obstructive uropathy. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 25th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 123.
Update Date 3/28/2016
Updated by: Scott Miller, MD, urologist in private practice in Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.