Children's Hospital Colorado
Urology

Ureteropelvic Junction Obstruction (UPJO)

We specialize in the big things, the small things and everything in between.

Best Children's Hospital by U.S. News & World Report Urology 2021-2 Badge

Get Care

Would you like to learn more about us?
Urology
Are you ready to schedule an appointment?
Schedule an appointment
Do you have questions about your child’s condition?
Call

What is ureteropelvic junction obstruction (UPJO)?

A ureteropelvic junction obstruction (UPJO) is an obstruction or blockage at the junction of the kidney and ureter. Under normal conditions, the kidneys filter the blood and remove waste in the form of urine. The urine then drains from the kidneys down through the ureters into the bladder. When a UPJO occurs, the amount of urine produced is more than the amount that can be drained through the ureter causing a 'backup' of urine. This in turn creates a collection of urine in the kidney, called hydronephrosis.

This illustration shows a kidney affected by ureteropelvic junction obstruction, which leads to hydronephrosis.

What causes UPJO?

The cause of UPJO is not well known, but abnormal tethering of the ureter or a narrowing of the ureter occurs during fetal development. The most common cause of an obstruction or blockage occurs while the child is still in the womb. UPJO is considered a congenital obstruction, meaning it is a condition that occurs at or before birth.

Who gets UPJO?

The cause of a UPJO is not well known, and therefore there is no known prevention for this condition.

Next steps

  • Would you like to learn more about us?

    Learn more about the Urology department
  • Do you have questions about your child’s condition?

    720-777-3926
  • Are you ready to schedule an appointment?

    Schedule an appointment

Get to know our pediatric experts.

Jeff Campbell, MD

Jeff Campbell, MD

Urology - Pediatric, Urology

Adriana Behr, CPNP-PC

Adriana Behr, CPNP-PC

Certified Pediatric Nurse Practitioner

Brian Miller, PA-C

Brian Miller, PA-C

Physician Assistant

Kyle Rove, MD

Kyle Rove, MD

Urology - Pediatric, Urology