Health Encyclopedia

Hydronephrosis of one kidney

Definition

Hydronephrosis is swelling of one kidney due to a backup of urine. This problem may occur in one kidney.

Alternative Names

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

Causes

Hydronephrosis (kidney swelling) occurs as the result of a disease. It is not a disease itself. Conditions that may lead to hydronephrosis include:

Blockage of a ureter due to scarring caused by prior infections, surgeries, or radiation treatments
Blockage from an enlarged uterus during pregnancy
Birth defects of the urinary system
Back flow of urine from bladder to kidney, called vesicoureteral reflux (may occur as a birth defect or due to an enlarged prostate or narrowing of the urethra)
Kidney stones
Cancers or tumors that occur in the ureter, bladder, 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.

Symptoms

Common symptoms include:

Flank pain
Abdominal mass, especially in children
Nausea and vomiting
Urinary tract infection (UTI)
Fever
Painful urination (dysuria)
Increased urinary frequency
Increased urinary urgency

In some cases, there may be no symptoms.

Exams and Tests

The condition is found on an imaging test such as:

Treatment

Treatment depends on the cause of the kidney swelling. Treatment may include:

Placing a stent (tube) through the bladder and ureter to allow urine to flow from the kidney into the 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 UTI.

Outlook (Prognosis)

Loss of kidney function, UTI, and pain may occur if the condition is left untreated.

Possible Complications

If hydronephrosis is not treated, 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. UTI and pain may also occur.

When to Contact a Medical Professional

Contact your health care provider if you have ongoing or severe flank pain, or fever, or if you think you may have hydronephrosis.

Prevention

Prevention of the disorders that cause this condition will prevent it from occurring.

References

Frøkiaer J. Urinary tract obstruction. In: Yu ASL, Chertow GM, Luyckx VA, Marsden PA, Skorecki K, Taal MW, eds. Brenner and Rector's The Kidney. 11th ed. Philadelphia, PA: Elsevier; 2020:chap 37.

Gallagher KM, Hughes J. Urinary tract obstruction. In: Feehally J, Floege J, Tonelli M, Johnson RJ, eds. Comprehensive Clinical Nephrology. 6th ed. Philadelphia, PA: Elsevier; 2019:chap 58.

Review Date:1/1/2022
Reviewed By:Kelly L. Stratton, MD, FACS, Associate Professor, Department of Urology, University of Oklahoma Health Sciences Center, Oklahoma City, OK. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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