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Unilateral hydronephrosis

Definition

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

See also:  Bilateral hydronephrosis

Alternative Names

Hydronephrosis; Chronic hydronephrosis; Acute hydronephrosis; Urinary obstruction

Causes, incidence, and risk factors

Hydronephrosis (kidney swelling) 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
  • Blockage of a ureter due to scarring, tumor, urinary stones
  • Chronic unilateral obstructive uropathy
  • (backflow of urine from bladder to kidney)Vesicoureteric reflux
  • (kidney stones)Nephrolithiasis
  • 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 found on an imaging test such as:

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.

Support Groups

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

Zeidel ML.Obstructive uropathy. In: Goldman L, Schafer AI, eds. . 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 125.

SinghI, Strandhoy JW, Assimos DG. Pathophysiology of urinary tract obstruction. In: Wein AJ, ed.. 10th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 40. 

Encyclopedia content is provided as information only and not intended to replace the advice and instruction from your personal physician.