Skip navigation

Unilateral hydronephrosis

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

Causes

Hydronephrosis (kidney swelling) occurs as the result of 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, or congenital abnormalities (present from birth)
  • 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 about 1 in 100 people.

Symptoms

Common symptoms include:

  • Flank pain
  • Abdominal mass
  • Nausea and vomiting
  • Urinary tract infection
  • 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:

  • A ureteral stent (tube that allows the ureter to drain into the bladder)
  • A nephrostomy tube (allows the blocked urine to drain out of the body into a drainage bag)
  • Antibiotics for infections

People who have only one kidney, who have immune system disorders such as diabetes or HIV, or who have had a transplant will need prompt treatment.

People who have long-term hydronephrosis may need antibiotics to reduce the risk of urinary tract infections.

Outlook (Prognosis)

Loss of kidney function may occur if the condition is left untreated.

Possible Complications

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.

When to Contact a Medical Professional

Call 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.

Alternative Names

Hydronephrosis; Chronic hydronephrosis; Acute hydronephrosis; Urinary obstruction

References

Zeidel ML. Obstructive uropathy. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Saunders Elsevier; 2011:chap 125.

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

Update Date: 3/26/2014

Updated by: Sovrin M. Shah, MD, Assistant Professor, Department of Urology, Albert Einstein College of Medicine, New York, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.

A.D.A.M Quality Logo

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 1997-2014, A.D.A.M., Inc. Duplication for commercial use must be authorized in writing by ADAM Health Solutions.

A.D.A.M Logo