Overview

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 care at Mayo Clinic

Source: http://www.mayoclinic.com

Symptoms

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:

• Pain
• 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

Source: http://www.mayoclinic.com

Causes

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

Source: http://www.mayoclinic.com

Diagnosis

Often, doctors diagnose ureteral obstruction disorders before birth during routine prenatal ultrasounds, which can show details of the developing fetus, including the kidneys, ureters and bladder. Doctors often perform another ultrasound after birth to re-evaluate the kidneys.

If your doctor suspects you have an obstructed ureter, some of these tests and scans might be used to reach a diagnosis:

• Blood and urine tests. Your doctor checks samples of your blood and urine for signs of infection and the presence of creatinine, which signals that your kidneys aren't working properly.
• Ultrasound. An ultrasound of the area behind your abdominal organs (retroperitoneal ultrasound) allows your doctor to view the kidneys and ureters.
• Voiding cystourethrogram. To test for abnormal urine flow, your doctor inserts a small tube (catheter) through the urethra, injects dye into your bladder, and takes X-rays of your kidneys, ureters, bladder and urethra before and during urination.
• Renal nuclear scan. Similar to an IVP, your doctor or a technician injects dye that contains a small amount of radioactive material into your arm. A special camera detects the radioactivity and produces images that your doctor uses to evaluate the urinary system.
• Cystoscopy. A small tube with a camera and light is inserted into your urethra or through a small incision. The optical system allows the doctor to see inside the urethra and bladder.
• Computerized tomography (CT) scan. A CT scan combines a series of X-ray views taken from many different angles and computer processing to create cross-sectional images of your kidneys, ureter and bladder.
• Magnetic resonance imaging (MRI). An abdominal MRI uses a magnetic field and radio waves to create detailed images of the organs and tissues that make up your urinary system.

Source: http://www.mayoclinic.com

Complications

Ureteral obstruction can lead to urinary tract infections and kidney damage, which can be irreversible.