The most common cause of chronic bilateral obstructive uropathy is a condition called bladder outlet obstruction . The kidneys produce urine in the normal manner but the urine cannot leave the bladder. Urine backs up, causing kidney swelling and damage.

When the blockage causes urine to back up into both kidneys, hydronephrosis (swelling of the kidneys) results. High blood pressure and kidney failure can result.

In men, chronic bilateral obstructive uropathy is most often a result of benign prostatic hyperplasia (BPH).

Other causes of chronic bilateral obstructive uropathy include:

• Bladder tumors
• Prostate tumors
• Tumors or masses of the uterus or other structures around the bladder neck or urethra
• Retroperitoneal fibrosis
• Narrowing of the urethra due to a birth defect or scar tissue

Chronic bilateral obstructive uropathy occurs in about 1 out of every 1,000 people.

Symptoms depend on the nature of the obstruction and where in the urinary tract the obstruction occurs.

Some of the most common symptoms of chronic obstructive uropathy include:

• Stronger and more frequent urge to urinate
• Difficulty initiating the flow of urine (urinary hesitancy )
• Dribbling of urine, incontinence
• Decreased urine output
• Decrease in the force of the urinary stream
• Increased need to urinate at night
• Burning or stinging with urination
• Feeling of incomplete emptying of the bladder
• Alternating times of increased urine output and decreased urine output
• Fever and chills (if there is also a urinary tract infection)

Additional symptoms that may be associated with this disease:

• Nail problems
• High blood pressure
• Abnormal urine color

A physical exam may show swollen or tender kidneys. The bladder may be large and full. A rectal examination may reveal an enlarged prostate. Blood pressure may be high.

Blood tests will be done to check kidney function, electrolyte balance, and blood cell counts. Urine tests may reveal a urinary tract infection.

Other tests that may be done:

• Abdominal ultrasound
• Bladder scan
• CT scan of abdomen and pelvis
• Kidney scan
• Uroflowmetry

The goal of treatment is to get rid of the blockage. You may need to stay in a hospital for a short while.

Treatment may include:

• Antibiotics to treat urinary tract infection
• Catheterization-- the placement of a tube into the body to drain urine (See: urinary catheters )
• Dialysis if kidney failure occurs
• Laser or heat therapy to shrink the prostate if the problem is due to an enlarged prostate
• Surgery such as transurethral resection of the prostate (TURP)
• Other types of surgery for disorders causing blockage of the urethra or bladder neck

Bilateral obstructive uropathy may be reversible if the blockage is corrected before kidney failure develops.

Chronic kidney failure leads to long-term kidney damage that can be life threatening.

Patients with a chronic blockage are at a higher risk for complications due to catheter use. Long-term catheter use (such as with a Foley catheter) may make the kidneys unable to concentrate urine. As a result, your body removes large amounts of urine that haven't been properly processed. This is called post-obstructive diuresis. It can be a life-threatening condition. Close monitoring is required.

If the obstruction was caused by cancer , the ultimate outcome depends on the disease severity and your response to treatment.

• Chronic kidney failure
• Complications due to long-term catheter use
• Chronic or recurrent urinary tract infection
• Long-term incontinence or urinary retention
• Formation of ureter or kidney stones

Call your health care provider if decreased urine output or other symptoms of chronic bilateral obstructive uropathy develop.

Routine screening (and treatment) for lower urinary tract disorders may help prevent this condition. A digital rectal exam is used to screen men for prostate problems.

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; 2004:741-742.