Obstructive uropathy is a condition in which the flow of urine is blocked, causing it to back up and injure one or both kidneys.
Uropathy - obstructive
Causes, incidence, and risk factors
Obstructive uropathy occurs when urine cannot drain through a ureter (a tube that carries urine from the kidneys to the bladder). Urine backs up into the kidney and causes it to become swollen (hydronephrosis).
Obstructive uropathy can affect one or both kidneys. It can occur suddenly, or be a long-term problem.
Common causes of obstructive uropathy include:
- Bladder stones
- Kidney stones
- Benign prostatic hyperplasia (enlarged prostate)
- Bladder or ureteral cancer
- Colon cancer
- Cervical cancer
- Uterine cancer
- Any cancer that spreads
- Scar tissue that occurs inside the ureters
- Problems with the nerves that supply the bladder
Obstructive uropathy may rarely occur during pregnancy. This is called idiopathic hydronephrosis of pregnancy.
Symptoms depend on whether the problem starts slowly or suddenly, and if one or both kidneys are involved. Symptoms may include:
- Mild to severe pain in the middle of the body (flank pain), felt on one or both sides
- Nausea or vomiting
Weight gain or swelling (edema)
You may also have problems passing urine, such as:
- Urge to urinate often
- Decrease in the force of urine stream
- Dribbling of urine
- Not feeling as if the bladder is emptied
- Need to urinate more often at night
- Decreased amount of urine
- Blood in urine
Signs and tests
The diagnosis of obstructive uropathy is made on imaging studies. Common radiographic studies used to diagnose obstructive uropathy include:
- Ultrasound of the belly area (abdomen) or pelvis
- CT scan of the belly area (abdomen) or pelvis
- Intravenous pyelogram (IVP)
- Voiding cystourethrogram
- Renal nuclear scan
Stents or drains placed in the ureter or in a part of the kidney called the renal pelvis may provide short-term relief of symptoms.
Nephrostomy tubes, which drain urine from the kidneys through the back, may be used to bypass the obstruction.
A Foley catheter, placed through the urethra into the bladder, may also be helpful.
Although short-term relief from the obstruction can be achieved without surgery, the cause of the obstruction must be removed and the urinary system repaired. Long-term relief from obstructive uropathy requires surgery.
If a sudden obstruction is rapidly diagnosed and repaired, kidney damage is less likely. Often, the damage to the kidneys goes away.
Long-term damage to the kidneys may occur if you have had obstructive uropathy for a long time.
If only one kidney is damaged, chronic kidney problems are less likely.
When both kidneys become damaged and fail to function even after the obstruction is repaired, you may need dialysis or a kidney transplant.
If the obstruction or blockage of the bladder was the cause, long-term damage to the bladder may occur. This may result in problems emptying the bladder or leaking urine.
Obstructive uropathy can cause permanent and severe damage to the kidneys, resulting in renal failure. Obstructive uropathy caused by bladder outlet obstruction can lead to permanent and severe damage to the bladder, resulting in problems such as incontinence and urinary retention.
Calling your health care provider
Contact your health care provider if you have symptoms of obstructive uropathy or believe that you may be suffering from this condition.
Obstructive uropathy can be prevented by addressing any underlying disorders that can cause it.
Zeidel ML. Obstructive uropathy. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 125.
Singh I, 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.