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:
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.
Common symptoms include:
In some cases, there may be no symptoms.
The condition is found on an imaging test such as:
Treatment depends on the cause of the kidney swelling. Treatment may include:
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.
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.
Reviewed 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.