Print Overview Female urinary system Enlarge image Close Female urinary system Female urinary system Your urinary system includes the kidneys, ureters, bladder and urethra. The urinary system removes waste from the body through urine. The kidneys are located toward the back of the upper abdomen. They filter waste and fluid from the blood and produce urine. Urine moves from the kidneys through narrow tubes to the bladder. These tubes are called the ureters. The bladder stores urine until it's time to urinate. Urine leaves the body through another small tube called the urethra. Male urinary system Enlarge image Close Male urinary system Male urinary system Your urinary system includes the kidneys, ureters, bladder and urethra. The urinary system removes waste from the body through urine. The kidneys are located toward the back of the upper abdomen. They filter waste and fluid from the blood and produce urine. Urine moves from the kidneys through narrow tubes to the bladder. These tubes are called the ureters. The bladder stores urine until it's time to urinate. Urine leaves the body through another small tube called the urethra. A ureteral obstruction is a blockage in one or both of the tubes (ureters) that carry urine from the kidneys to the bladder. Ureteral obstruction can be cured. 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.Products & ServicesA Book: Mayo Clinic Family Health BookNewsletter: Mayo Clinic Health Letter — Digital EditionShow more products from Mayo Clinic SymptomsUreteral 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: Pain. Changes in how much urine you produce (urine output). Difficulty urinating. Blood in the urine. Urinary tract infections. High blood pressure (hypertension). When to see a doctorMake an appointment with your health care provider if you have signs and symptoms that worry you. Seek 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. Request an appointment Causes Duplicated ureter and ureterocele Enlarge image Close Duplicated ureter and ureterocele Duplicated ureter and ureterocele A duplicated ureter occurs when two ureters form on the same kidney. A ureterocele is a small bulge in the ureter, usually in the end closest to the bladder. Both conditions may lead to ureteral obstruction. Different types of ureteral obstruction have different causes, some of them present at birth (congenital). They include: A second (duplicated) ureter. This common condition, which is congenital, causes two ureters to form on the same kidney. The second ureter can be fully or only partially developed. If either ureter doesn't work properly, urine can back up into the kidney and cause damage. A blockage (obstruction) where the ureter connects to the kidney or bladder. This prevents urine flow. A blockage where the ureter and kidney meet (ureteropelvic junction) may cause the kidney to swell and eventually stop working. This condition can be congenital or can develop with typical childhood growth, result from an injury or scarring, or in rare cases, develop from a tumor. A blockage where the ureter and bladder meet (ureterovesical junction) may cause urine to back up into the kidneys. Ureterocele. If a ureter is too narrow and doesn't allow urine to flow completely, a tiny bulge in the ureter (ureterocele) may develop. When a ureterocele develops, it's 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 as the result of cancer tumors or 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 causesVarious causes inside (intrinsic) or outside (extrinsic) the ureter can lead to ureteral obstruction, including: Kidney stones. Cancerous and noncancerous tumors. Blood clots. Enlarged lymph nodes. 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. Risk factorsCertain conditions present at birth can increase the risk of having ureteral obstruction. Having kidney stones or bladder stones also might increase the risk that one of the ureters becomes blocked. Blood clots, tumors, certain tissue growth and enlarged lymph nodes might also be factors in developing this condition. ComplicationsUreteral obstruction can lead to urinary tract infections and kidney damage, which can be irreversible. By Mayo Clinic Staff Ureteral obstruction care at Mayo Clinic Request an appointment Diagnosis & treatment Jan. 26, 2024 Print Show references Zeidel ML, et al. Clinical manifestations and diagnosis of urinary tract obstruction and hydronephrosis. https://www.uptodate.com/contents/search. Accessed Oct. 1, 2021. Yu ASL, et al., eds. Urinary tract obstruction. In: Brenner & Rector's The Kidney. 11th ed. Elsevier; 2020. https://www.clinicalkey.com. Accessed Oct. 9, 2021. Obstructive uropathy. Merck Manual Professional Version. https://www.merckmanuals.com/professional/genitourinary-disorders/obstructive-uropathy/obstructive-uropathy#. Accessed Oct. 1, 2021. AskMayoExpert. Ureteropelvic junction obstruction (adult). Mayo Clinic; 2021. Gargollo PC (expert opinion). Mayo Clinic. Oct. 28, 2021. Tabib C, et al. Management and treatment options when facing malignant ureteral obstruction. International Journal of Urology. 2020; doi:10.1111/iju.14235. Braswell Pickering EA. Allscripts EPSi. Mayo Clinic. July 15, 2021. Related Duplicated ureter and ureterocele Associated Procedures Computerized tomography (CT) urogram Products & Services A Book: Mayo Clinic Family Health Book Newsletter: Mayo Clinic Health Letter — Digital Edition Show more products and services from Mayo Clinic Ureteral obstructionSymptoms&causesDiagnosis&treatmentDoctors&departmentsCare atMayoClinic Advertisement Mayo Clinic does not endorse companies or products. 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