Health Encyclopedia

Bilateral hydronephrosis

Definition

Bilateral hydronephrosis is the enlargement of the parts of the kidney that collect urine. Bilateral means both sides.

Alternative Names

Hydronephrosis - bilateral

Causes

Bilateral hydronephrosis occurs when urine is unable to drain from the kidney into the bladder. Hydronephrosis is not itself a disease. It occurs as a result of a problem that prevents urine from draining out of the kidneys, ureters, and bladder.

Disorders linked with bilateral hydronephrosis include:

Acute bilateral obstructive uropathy -- sudden blockage of the kidneys
Bladder outlet obstruction -- blockage of the bladder, which does not allow drainage
Chronic bilateral obstructive uropathy -- a gradual blockage of both kidneys is most often from a common singular obstruction
Neurogenic bladder -- poorly functional bladder
Posterior urethral valves -- flaps on the urethra that causes poor emptying of the bladder (in boys)
Prune belly syndrome -- poorly emptying bladder that causes distention of the belly
Retroperitoneal fibrosis -- abnormal scar tissue that blocks the ureters
Ureteropelvic junction obstruction -- blockage of the kidney at the point where the ureter enters the kidney
Vesicoureteric reflux -- backup of the urine from the bladder up to the ureter or kidney
Uterine prolapse -- when the bladder drops down and presses into the vaginal area. This causes a kink in the urethra, which prevents the urine from emptying out of the bladder.

Symptoms

In a baby, signs of a problem are often found before birth during a pregnancy ultrasound.

A urinary tract infection in a newborn baby can signal a blockage in the kidney. An older child who gets repeat urinary tract infections should also be checked for blockage.

A higher than normal number of urinary tract infections is often the only symptom of the problem.

Common symptoms in adults may include:

Back pain
Nausea, vomiting
Fever
Need to urinate often
Decreased urine output
Blood in the urine
Urinary incontinence

Exams and Tests

The following tests can show bilateral hydronephrosis:

CT scan of the abdomen or kidneys
Intravenous pyelogram (IVP), used less often
Pregnancy (fetal) ultrasound
Renal scan
Ultrasound of the abdomen or kidneys

Treatment

Placing a tube into the bladder (Foley catheter) may open the blockage. Other treatments include:

Draining the bladder
Relieving pressure by placing tubes in the kidney through the skin
Placing a tube (stent) through the ureter to allow urine to flow from the kidney to bladder

The underlying cause of the blockage needs to be found and treated once the buildup of urine is relieved.

Outlook (Prognosis)

Surgery performed while the baby is in the womb or shortly after birth can have good results in improving kidney function.

Return of renal function can vary, depending on how long the blockage is present.

Possible Complications

Irreversible kidney damage may result from conditions that cause hydronephrosis.

When to Contact a Medical Professional

This problem is often found by the health care provider.

Prevention

An ultrasound during pregnancy can show a blockage in the baby's urinary tract. This allows the problem to be treated with early surgery.

Other causes of blockage, such as kidney stones, can be detected early if people notice warning signs of kidney problems.

It is important to pay attention to general problems with urination.

References

Elder JS. Obstruction of the urinary tract. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 555.

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.

Nakada SY, Best SL. Management of upper urinary tract obstruction. In: Partin AW, Dmochowski RR, Kavoussi LR, Peters CA, eds. Campbell-Walsh-Wein Urology. 12th ed. Philadelphia, PA: Elsevier; 2021:chap 89.

Review Date:4/1/2023
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 C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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