Table of ContentsView AllTable of ContentsSymptomsCausesDiagnosisTreatment
Table of ContentsView All
View All
Table of Contents
Symptoms
Causes
Diagnosis
Treatment
Ureteropelvic junction (UPJ) obstruction is a condition where the part of the kidney that normally drains urine becomes blocked. This blockage prevents the normal flow of urine out of the kidney and into the bladder, which can lead to kidney damage and swelling (calledhydronephrosis).
UPJ obstruction is usually congenital, meaning it stems from kidney development problems in a fetus. Less commonly, UPJ obstruction is acquired.
In infants, symptoms of UPJ obstruction may include a mass in the abdomen, blood in the urine, and failure to thrive. Older children and adults may experience intermittent flank pain that worsens with caffeine consumption (or alcohol in adults) and nausea and vomiting.
Several tests are used to diagnose UPJ obstruction, including blood and urine tests and various imaging tests to visualize the urinary tract system. The treatment of UPJ obstruction requires surgery in order to relieve the obstruction; although, in many cases, especially in infants, the obstruction resolves on its own, so surgery is avoided.
lukaves/Getty Images
Ureteropelvic Junction Obstruction Symptoms
The symptoms of ureteropelvic junction obstruction depend on the age of the patient.
Infants
Since UPJ blocks normal urine flow, the affected kidney will become swollen. This kidney swelling is called hydronephrosis, and in congenital UPJ obstruction, is usually seen on a prenatal ultrasound, while the fetus is still growing in a mother’s womb.
Once born, an infant may have a mass in their abdomen that can be felt. This mass represents the enlarged, swollen kidney.
Other potential symptoms of UPJ obstruction in an infant may include:
Possible Symptoms of Urinary Tract Infection in InfantsFever (sometimes the only symptom)IrritabilityFoul-smelling urinePoor feedingVomitingIncreased or decreased number of wet diapersDiscomfort with urination
Possible Symptoms of Urinary Tract Infection in Infants
Fever (sometimes the only symptom)IrritabilityFoul-smelling urinePoor feedingVomitingIncreased or decreased number of wet diapersDiscomfort with urination
Older Children and Adults
In older children and adults, (in which the congenital UPJ obstruction remained undiagnosed or is acquired), the following symptoms may occur:
Urinary Tract Infections
In some cases, a patient has no symptoms of UPJ obstruction, but hydronephrosis is seen incidentally on an imaging test ordered for unrelated symptoms.
You have two bean-shaped organs called kidneys located in each flank, which is the area at the back of your abdomen, below your ribcage, and next to your spine.
Attached to each kidney is a long, thin tube called a ureter. The function of the ureter is to carry the urine produced in the kidney to the bladder, where it is eventually urinated out.
Ureteropelvic junction obstruction occurs when the junction (called the renal pelvis) that attaches the kidney to the ureter becomes blocked. This blockage either slows down or stops the normal flow of urine from the kidney to the bladder.
In most cases, the blockage is congenital, meaning some sort of abnormality within the kidney or ureter developed before birth. Much less commonly, UPJ obstruction is acquired.
Congenital
The congenital abnormalities that may lead to UPJ obstruction include:
Acquired
Less commonly, the blockage is acquired and not present at birth.
This may occur as a result of the following:
While the diagnosis of UPJ obstruction may be suspected when hydronephrosis is seen as an ultrasound, other tests are needed to confirm the diagnosis.
An Overview of Hydronephrosis
Blood and Urine Tests
Various blood and urine tests will be ordered to evaluate a person’s kidney function, includingblood urea nitrogen (BUN)and creatinine clearance.
Renal Test Analyzer: Decode Your Results
Additional Imaging Studies
Computed tomography (CT) scanormagnetic resonance imaging (MRI)studies may be ordered to better visualize the kidney and ureter and the associated blockage
Intravenous Pyelogram
Nuclear Renography
Voiding Cystourethrogram
Avoiding cystourethrogramis an X-ray test that visualizes whether dye injected into the bladder (through a catheter) refluxes back into the ureters and whether there are any blockages in the urethra. These two problems—calledvesicoureteral reflux (VUR)and posterior urethral valves (PUV), respectively—are additional causes of hydronephrosis in infants.
Many cases of UPJ obstruction (especially in infants) improve and resolve on their own. During the watching and waiting time, antibiotics may be prescribed to prevent infection.
If the obstruction doesn’t improve, which may cause chronic flank or abdominal pain, recurrent infections, worsening kidney function, and/or significant hydronephrosis, a surgery called pyeloplasty may be required.
Pyeloplasty entails reconstructing the renal pelvis, which is the attachment site of the ureter to the kidney, and the source of a UPJ obstruction.
The goals of pyeloplasty are to improve urine flow and reduce kidney damage and infection.
There are two types of pyeloplasty—open and laparoscopic. Laparoscopic pyeloplasty is the more common approach in adults.
Open pyeloplastyinvolves accessing the affected renal pelvis through a 2- to 3-inch cut in the abdomen, just below the ribcage.
After surgery, follow-up care with periodic kidney ultrasounds and kidney function testing is required.
A Word From Verywell
5 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Borin JF.Ureteropelvic junction obstruction in adults.Rev Urol. 2017;19(4):261-64. doi:10.3909/riu0781Hu G, Luo M, Xu Y.Giant hydronephrosis secondary to ureteropelvic junction obstruction in adults: report of a case and review of literatures.Int J Clin Exp Med; 8(3):4715–4717.Krajewski W, Wojciechowska J, Dembowski J, Zdrojowy R, Szydelko T.Hydronephrosis in the course of ureteropelvic junction obstruction: An underestimated problem? Current opinions on the pathogenesis, diagnosis and treatment.Adv Clin Exp Med.2017;26(5):857-864. doi:10.17219/acem/59509Urology Care Foundation.What is ureteropelvic junction obstruction?Turra F, Escolino M, Farina A, Settimi A, Esposito C, Varlet F.Pyeloplasty techniques using minimally invasive surgery (MIS) in pediatric patients.Transl Pediatr.2016; 5(4): 251–255. doi:10.21037/tp.2016.10.05Additional ReadingJohn Hopkins Medicine.Ureteropelvic junction obstruction.Khan F, Ahmed K, Lee N, Challacombe B, Khan MS, Dasgupta P.Management of ureteropelvic junction obstruction in adults.Nat Rev Urol. 2014;11(11):629-38. doi:10.1038/nrurol.2014.240Leung AKC, Wong AHC, Leung AAM, Hon KL.Urinary tract infection in children.Recent Pat Inflamm Allergy Drug Discov. 2019;13(1):2-18. doi:10.2174/1872213X13666181228154940
5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Borin JF.Ureteropelvic junction obstruction in adults.Rev Urol. 2017;19(4):261-64. doi:10.3909/riu0781Hu G, Luo M, Xu Y.Giant hydronephrosis secondary to ureteropelvic junction obstruction in adults: report of a case and review of literatures.Int J Clin Exp Med; 8(3):4715–4717.Krajewski W, Wojciechowska J, Dembowski J, Zdrojowy R, Szydelko T.Hydronephrosis in the course of ureteropelvic junction obstruction: An underestimated problem? Current opinions on the pathogenesis, diagnosis and treatment.Adv Clin Exp Med.2017;26(5):857-864. doi:10.17219/acem/59509Urology Care Foundation.What is ureteropelvic junction obstruction?Turra F, Escolino M, Farina A, Settimi A, Esposito C, Varlet F.Pyeloplasty techniques using minimally invasive surgery (MIS) in pediatric patients.Transl Pediatr.2016; 5(4): 251–255. doi:10.21037/tp.2016.10.05Additional ReadingJohn Hopkins Medicine.Ureteropelvic junction obstruction.Khan F, Ahmed K, Lee N, Challacombe B, Khan MS, Dasgupta P.Management of ureteropelvic junction obstruction in adults.Nat Rev Urol. 2014;11(11):629-38. doi:10.1038/nrurol.2014.240Leung AKC, Wong AHC, Leung AAM, Hon KL.Urinary tract infection in children.Recent Pat Inflamm Allergy Drug Discov. 2019;13(1):2-18. doi:10.2174/1872213X13666181228154940
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Borin JF.Ureteropelvic junction obstruction in adults.Rev Urol. 2017;19(4):261-64. doi:10.3909/riu0781Hu G, Luo M, Xu Y.Giant hydronephrosis secondary to ureteropelvic junction obstruction in adults: report of a case and review of literatures.Int J Clin Exp Med; 8(3):4715–4717.Krajewski W, Wojciechowska J, Dembowski J, Zdrojowy R, Szydelko T.Hydronephrosis in the course of ureteropelvic junction obstruction: An underestimated problem? Current opinions on the pathogenesis, diagnosis and treatment.Adv Clin Exp Med.2017;26(5):857-864. doi:10.17219/acem/59509Urology Care Foundation.What is ureteropelvic junction obstruction?Turra F, Escolino M, Farina A, Settimi A, Esposito C, Varlet F.Pyeloplasty techniques using minimally invasive surgery (MIS) in pediatric patients.Transl Pediatr.2016; 5(4): 251–255. doi:10.21037/tp.2016.10.05
Borin JF.Ureteropelvic junction obstruction in adults.Rev Urol. 2017;19(4):261-64. doi:10.3909/riu0781
Hu G, Luo M, Xu Y.Giant hydronephrosis secondary to ureteropelvic junction obstruction in adults: report of a case and review of literatures.Int J Clin Exp Med; 8(3):4715–4717.
Krajewski W, Wojciechowska J, Dembowski J, Zdrojowy R, Szydelko T.Hydronephrosis in the course of ureteropelvic junction obstruction: An underestimated problem? Current opinions on the pathogenesis, diagnosis and treatment.Adv Clin Exp Med.2017;26(5):857-864. doi:10.17219/acem/59509
Urology Care Foundation.What is ureteropelvic junction obstruction?
Turra F, Escolino M, Farina A, Settimi A, Esposito C, Varlet F.Pyeloplasty techniques using minimally invasive surgery (MIS) in pediatric patients.Transl Pediatr.2016; 5(4): 251–255. doi:10.21037/tp.2016.10.05
John Hopkins Medicine.Ureteropelvic junction obstruction.Khan F, Ahmed K, Lee N, Challacombe B, Khan MS, Dasgupta P.Management of ureteropelvic junction obstruction in adults.Nat Rev Urol. 2014;11(11):629-38. doi:10.1038/nrurol.2014.240Leung AKC, Wong AHC, Leung AAM, Hon KL.Urinary tract infection in children.Recent Pat Inflamm Allergy Drug Discov. 2019;13(1):2-18. doi:10.2174/1872213X13666181228154940
John Hopkins Medicine.Ureteropelvic junction obstruction.
Khan F, Ahmed K, Lee N, Challacombe B, Khan MS, Dasgupta P.Management of ureteropelvic junction obstruction in adults.Nat Rev Urol. 2014;11(11):629-38. doi:10.1038/nrurol.2014.240
Leung AKC, Wong AHC, Leung AAM, Hon KL.Urinary tract infection in children.Recent Pat Inflamm Allergy Drug Discov. 2019;13(1):2-18. doi:10.2174/1872213X13666181228154940
Meet Our Medical Expert Board
Share Feedback
Was this page helpful?Thanks for your feedback!What is your feedback?OtherHelpfulReport an ErrorSubmit
Was this page helpful?
Thanks for your feedback!
What is your feedback?OtherHelpfulReport an ErrorSubmit
What is your feedback?
