Ureteral Obstruction


What is ureteral obstruction?

A ureteral obstruction is a blockage in one or both of the ureters. Ureters are the tubes that carry urine from the kidneys to the bladder. Ureters can become blocked for a variety of reasons.

A ureteral obstruction prevents urine from moving into your bladder and out of your body. If this blockage isn’t treated, urine can back up and damage your kidneys. This can cause pain and put you at risk of infection. In severe cases, a ureteral obstruction can lead to kidney failure, sepsis (life-threatening infection) or death.

How common is ureteral obstruction?

Ureteral obstructions are fairly common. They are more common in men over 60 because the prostate (a gland that only men have, located around the outflow of the bladder) becomes enlarged as men age. The enlarged prostate can block the flow of urine and result in buildup of urine in the bladder. It can also push up against the ureter and cause a blockage. Another form of bladder outflow blockage is by buildup of pressure in the urinary bladder because of an injury to the nerves or weak muscles—which makes it more difficult for the ureters to empty.

Other causes of blockages can include:

  • Kidney stones: This form of blockage is very common and can happen to both men and women. Kidney stones can affect young and old patients.
  • Scarring: When the tube that transfers urine from the kidney to the bladder is scarred on the inside, you can experience a blockage. This can also be caused by a birth defect.
  • Pressure from outside structures: You can also have a blockage when something outside of the ureter presses on it. This could be caused by a tumor or another nearby organ.

Who is affected by ureteral obstruction?

People of all ages can have a blocked ureter. Patients with kidney stones, can have a blockage at any age. These blockages can happen in both men and women. Older men with enlarged prostates can also affected. In babies and children who have a ureteral obstruction, the cause is usually a birth defect that affects their urinary tract.

Symptoms and Causes

What are the symptoms of ureteral obstruction?

Signs of ureteral obstruction reveal themselves in different ways. Patients who have stones may have severe pain. When the blockage is gradual and slow, it usually come on slowly and builds over time. In some cases symptoms may be mild at first, but can quickly get worse. Symptoms of a blocked ureter or urinary tract obstruction include:

  • Pain in your abdomen, lower back or sides below your ribs (flank pain).
  • Fever, nausea or vomiting.
  • Difficulty urinating or emptying your bladder.
  • Frequent urination.
  • Recurring urinary tract infections (UTI).
  • Urine that is bloody or cloudy.
  • Swollen leg(s).

How do people get ureteral obstruction?

There are many different reasons why the ureter can become blocked. Causes of a ureteral obstruction include:

Diagnosis and Tests

How are ureteral obstructions diagnosed?

To diagnose a ureteral obstruction, your doctor may:

  • Check your urine and blood for signs of infection, which may suggest that the kidneys aren’t working well.
  • Perform an MRI, CT scan, or ultrasound to find the location and cause of the blockage. Additional tests may be needed per the findings.

Management and Treatment

How do I know if I have ureteral obstruction?

If you suspect you have ureteral obstruction, you should see your doctor. Some of the signs of a blocked ureter are similar to symptoms of other conditions that need treatment, such as urinary tract infections (UTI), having pain, or not getting good urine output even when you drink plenty of fluids. It’s important to see your doctor for diagnosis and treatment.

What are the treatments for ureteral obstruction?

The treatment you receive depends on the reason for the blockage. First, your doctor will perform a procedure to allow the urine to drain from your body. These procedures include:

  • Inserting a ureteral stent: Doctors insert a thin tube in the ureter that holds the ureter open so urine can drain freely.
  • Placing a catheter in the kidney: In this procedure, doctors create an opening, called a nephrostomy, in the skin near the kidney. They insert a catheter into the opening and drain urine directly from the kidney.
  • Placing a catheter in the urinary bladder: This procedure is used if the blockage is at the outflow of urine from the bladder.
  • After draining the urine, your doctor will address the reason for the blockage. Your doctor’s approach will depend on what caused the obstruction and the severity of the blockage.

Common treatments for ureteral obstruction are:

  • Medication: If an enlarged prostate is causing the blockage, doctors may prescribe:
    • An alpha-blocker to relax the muscles of the prostate.
    • A medicine called finasteride (Proscar®) that causes the prostate to shrink.
  • Surgery: If the blockage is due to a birth defect or tumor, doctors can often perform surgery to remove the obstruction.
  • Stent: Doctors can insert a stent (a thin, flexible tube) into the ureter to keep it open and allow urine to flow.

What are the side effects of the treatment for ureteral obstruction?

The side effects of alpha-blockers include dizziness, headaches and fainting. Side effects of finasteride (Proscar®), the medication used to shrink the prostate, include decreased sexual desire and increased hair growth.

Surgery to remove the obstruction or place a stent can have side effects such as discomfort and increased risk of infection.

What are the complications associated with ureteral obstruction?

When urine cannot leave the body and starts to build up in the kidneys, it is called obstructive uropathy. Obstructive uropathy can lead to hydronephrosis (swelling of the kidneys). If left untreated, obstruction of the ureter can cause serious problems like kidney failure, sepsis and death.

What can I do to help relieve symptoms of ureteral obstruction?

If you have symptoms of ureteral obstruction, you should see your doctor right away. Symptoms can get worse if left untreated. Only a doctor can diagnose and treat ureteral obstruction.


How can you prevent ureteral obstruction?

There is no way to prevent ureteral obstruction caused by:

  • A genetic condition.
  • Tumor.
  • Vascular disease.
  • GI issues.
  • Enlarged prostate.

To avoid developing a ureteral stone, one of the causes of ureteral obstruction, you should drink plenty of water and limit your sodium (salt) intake.

Outlook / Prognosis

What is the prognosis (outlook) for patients who have ureteral obstruction?

The outlook for ureteral obstruction depends on whether the kidneys were damaged while urine was unable to drain. If doctors fix the blockage before serious kidney damage occurs, ureteral obstruction doesn’t usually have serious long-term effects. In severe cases, kidney failure and death can result from a ureteral obstruction if it is left untreated.

Living With

When should I call my doctor about ureteral obstruction?

If you have signs of ureteral obstruction, you should call your doctor right away. Symptoms may be mild at first but can get worse quickly and can be very serious.

Last reviewed by a Cleveland Clinic medical professional on 10/21/2019.


  • Merck Manual. Urinary Tract Obstruction. (https://www.merckmanuals.com/home/kidney-and-urinary-tract-disorders/obstruction-of-the-urinary-tract/urinary-tract-obstruction) Accessed 10/25/2019.
  • Urology Care Foundation. What is Extrinsic Obstruction of the Ureter? (https://www.urologyhealth.org/urologic-conditions/extrinsic-obstruction-of-the-ureter) Accessed 10/25/2019.
  • Radiological Society of North America, Inc., American College of Radiology. Ureteral Stenting and Nephrostomy. (https://www.radiologyinfo.org/en/info.cfm?pg=ureteralnephro) Accessed 10/25/2019.

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