Home > Medical Reference > Encyclopedia (English)

Toggle: English / Spanish

Ask Our Experts

Get answers to your specific medical questions from UM Medical Center experts.

Note: This is for informational purposes only. Doctors cannot provide a diagnosis via e-mail.

 

Related Content

Hospital for Children

Divisions/Specialties

Patient Success Stories

Our Doctors

UPJ obstruction

Definition:

Ureteropelvic junction (UPJ) obstruction is a blockage in the area that connects the renal pelvis (part of the kidney) to one of the tubes (ureters) that move urine to the bladder.

Alternative Names:

Ureteropelvic junction obstruction; UP junction obstruction; Obstruction of the ureteropelvic junction

Causes, incidence, and risk factors:

UPJ obstruction generally occurs when a baby is still growing in the womb. This is called a congenital condition (present from birth). Most of the time, the blockage is caused when the connection between the ureter and the renal pelvis narrows. This causing urine to build up, damaging the kidney.

The condition can also be caused when a blood vessel is located in the wrong position over the ureter. In older children and adults, UPJ obstruction can be due to scar tissue, infection, previous treatments for a blockage, or kidney stones.

UPJ obstruction is the most frequently diagnosed cause of urinary obstruction in children. It is now commonly diagnosed during prenatal ultrasound studies. In some cases, the condition isn't seen until after birth. Children may have an abdominal mass or a urinary tract infection

The most severe cases of UPJ obstruction may require surgery early in life. However, the majority of cases may not require surgery until later in life, and some cases do not require surgery at all.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process . A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 1997-2007 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

adam.com