A ureteral obstruction is a blockage in one or both of the tubes (ureters) that carry urine from your kidneys to your bladder. Ureteral obstruction can be curable. However, if it's not treated, symptoms can quickly move from mild — pain, fever and infection — to severe — loss of kidney function, sepsis and death.
Ureteral obstruction is fairly common. Because it's treatable, severe complications are rare.
Ureteral obstruction might have no signs or symptoms. Signs and symptoms depend on where the obstruction occurs, whether it's partial or complete, how quickly it develops, and whether it affects one or both kidneys.
Signs and symptoms might include:
- Changes in the amount of urine produced
- Difficulty urinating
- Blood in the urine
- Repeated urinary tract infections
- High blood pressure (hypertension)
When to see a doctor
Make an appointment with your doctor if you have signs and symptoms that worry you.
Seek immediate medical attention if you experience:
- Pain so severe that you can't sit still or find a comfortable position
- Pain accompanied by nausea and vomiting
- Pain accompanied by fever and chills
- Blood in your urine
- Difficulty passing urine
Different types of ureteral obstruction have different causes, some of them present at birth (congenital). They include:
Ureteral obstruction may be caused by:
- Duplication of the ureter, the tube that carries urine from the kidney to the bladder. This common condition, which is present at birth (congential), causes two ureters to form on the same kidney. The second ureter can be normal or only partially developed. If either ureter doesn't function properly, urine can back up into the kidney and cause damage.
- An abnormality where the ureter connects to the bladder or the kidney, which blocks urine flow. An abnormal connection between the ureter and kidney (ureteropelvic junction) may cause the kidney to swell and eventually stop working. This abnormality can be congenital or it can develop with normal childhood growth, result from an injury or scarring, or in rare cases, develop from a tumor. An abnormal connection between the ureter and bladder (ureterovesical junction) may cause urine to back up into the kidneys.
- Ureterocele. If the ureter is too narrow and doesn't allow urine to flow normally, a tiny bulge in the ureter (ureterocele) may develop, usually in the section of the ureter closest to the bladder. This can block urine flow and cause urine to back up into the kidney, possibly leading to kidney damage.
- Retroperitoneal fibrosis. This rare disorder occurs when fibrous tissue grows in the area behind the abdomen. The fibers may grow due to cancers or may result from taking certain medicines used to treat migraines. The fibers encircle and block the ureters, causing urine to back up into the kidneys.
Other possible causes
Various causes inside (intrinsic) or outside (extrinsic) the ureter can lead to ureteral obstruction, including:
- Ureteral stones
- Severe constipation, which happens primarily in children but also occurs in adults
- Cancerous and noncancerous tumors
- Internal tissue growth, such as endometriosis in females
- Long-term swelling of the ureter wall, usually due to diseases such as tuberculosis or a parasite infection called schistosomiasis
Ureteral obstruction can lead to urinary tract infections and kidney damage, which can be irreversible.