Health Encyclopedia

Unilateral hydronephrosis

Definition

Unilateral hydronephrosis is swelling of one kidney due to a backup of urine.

Alternative Names

Hydronephrosis

Causes, incidence, and risk factors

Hydronephrosis is a condition that occurs with a disease. It is not a disease itself. Conditions that are often associated with unilateral hydronephrosis include:

Acute unilateral obstructive uropathy
Chronic unilateral obstructive uropathy
Vesicoureteric reflux (backflow of urine from bladder to kidney)
Nephrolithiasis (kidney stones)
Hydronephrosis that occurs without a known cause during pregnancy

Unilateral hydronephrosis occurs in approximately 1 in 100 people.

Symptoms

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

Note: Sometimes unilateral hydronephrosis does not have symptoms.

Signs and tests

Unilateral hydronephrosis is usually identified with tests such as the following:

Abdominal MRI
CT scan of the kidneys or abdomen
Intravenous pyelogram (IVP)
Isotope renography (special scan of the kidneys)
Ultrasound of the kidneys or abdomen

Treatment

Treatment and prognosis for unilateral hydronephrosis depend on what is causing the kidney swelling. Treatment may include:

A ureteral stent (tube that allows the ureter to drain into the bladder)
A nephrostomy tube (allows the blocked urine to drain through the back)
Antibiotics for infections

Patients who have only one kidney, who have immune-compromising disorders such as diabetes or HIV, or who have received a transplant should be treated promptly.

Preventative antibiotics may be prescribed to decrease the risk of urinary tract infections in patients who have long-term hydronephrosis.

Expectations (prognosis)

Prolonged hydronephrosis results in the eventual loss of kidney function.

Complications

If hydronephrosis is left untreated, the affected kidney may be permanently damaged. Kidney insufficiency or kidney failure is rare with unilateral hydronephrosis because the other kidney usually functions normally. However, if the patient has only one functioning kidney, kidney failure will occur.

Calling your health care provider

Call your health care provider if you have prolonged or severe flank pain, or if you suspect hydronephrosis.

Prevention

Prevention of the disorders associated with unilateral hydronephrosis will prevent this condition.

References

Wein AJ, et al. Campbell-Walsh Urology. 9th ed. St. Louis, Mo: WB Saunders; 2007.

Goldman L, Ausiello D, et al. Cecil Textbook of Medicine, 22nd ed. Philadelphia, Pa: WB Saunders; 2004.

Review Date:1/24/2008
Reviewed By:Marc A. Greenstein, D.O., F.A.C.O.S. Urologist, Somerset Medical Center in Somerville, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

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