Acute unilateral obstructive uropathy is a sudden blockage in one or both of the tubes (ureters) that drain urine from the kidneys.

Unilateral obstructive uropathy is most often caused by a kidney stone, although injury or other conditions could cause the disorder.

When urine flow is blocked, it backs up into the kidney. This leads to kidney swelling, also called hydronephrosis.

You have a greater risk for unilateral obstructive uropathy if you have ureteral stones and tumors, kidney stones, and tumors in nearby such as the uterus and cervix.

Acute unilateral obstructive uropathy occurs in 1 in 1,000 people.

• Severe flank pain or pain in the side
  • Severe enough to require strong pain medicine
  • Pain on one side; it may move to the groin, genitals, and thigh
  • Pain comes and goes; intensity changes over minutes
• Nausea
• Vomiting
• Back pain, may be on only one side
• Abdominal pain, right or left lower quadrant
• Blood in the urine
• Abnormal urine color (tan, cola colored, tea colored)
• High blood pressure that has increased recently (within 2 weeks)
• Urinary tract infection
• Fever
• Urinary frequency
• Urinary urgency
• Foul-smelling urine
• Mental status changes

The health care provider will perform a physical exam. Palpation of the belly area reveals an swollen or tender kidney. Blood pressure may be high.

The following tests may be done:

• Urinalysis
• Urine culture
• CBC
• Basic metabolic panel

Hydronephrosis or obstruction of the ureter may appear on these tests:

• Intravenous pyelogram (IVP)
• Abdominal ultrasound
• Abdominal CT scan
• Renal nuclear scan

The goal of treatment is to relieve or reduce the blockage.

Antibiotics may be given if there is a urinary tract infection.

Stents or drains placed in the ureter or nearby area may provide short-term relief of symptoms. Surgery to repair the underlying cause of the obstruction will usually cure the problem.

Kidney surgery, including nephrectomy may be needed if kidney function is poor or if there is a bad infection.

The outcome varies. The disorder may result in permanent damage to the kidney. However, kidney failure usually does not result because the second kidney continues to function.

• Permanent failure of the affected kidney (chronic renal failure)
• Chronic unilateral obstructive uropathy
• Chronic or recurrent urinary tract infection
• Hypertension

Call your health care provider if flank pain or other symptoms of acute unilateral obstructive uropathy develop.

Call your health care provider if symptoms worsen during or after treatment, or if new symptoms develop.

If you are prone to kidney stones, drink plenty of water (6 to 8 glasses per day) to reduce the chances of their formation.

Research suggests that a diet low in sodium and oxalate and high in citrate significantly reduces risk of calcium-based kidney stone formation. Consult with a nutritionist for more information on such diets.

Seek medical attention if kidney stones persist or recur to identify the cause and to prevent new stones from forming.