PUJ Obstruction

What Is PUJ Obstruction?

This is where the top end of the tube that drains urine from the kidney (ureter) is blocked, hence not allowing urine to drain out of the kidney.

It can be present at birth (congenital) or come about as an adult (acquired).

It is commonly unilateral.


PUJ obstruction may not cause any symptoms and are found accidentally when scans are done for other reasons. When they do cause symptoms they include

  • Intermittent pain in the back after drinking large volumes of fluid or alcohol
  • Frequent UTIs
  • Stone formation

Causes Of PUJ Obstruction

Causes of PUJ obstruction can be congenital or acquired.

Congenital causes include:

  • Abnormal muscle arrangement at PUJ
  • Persistent fold in ureter
  • Persistent blood vessel to the kidney causing compression of the PUJ (crossing vessel)

Acquired causes include:

  • Obstructing stone
  • Infection causing scarring
  • Cancer of ureter


Diagnosis requires 2 forms of imaging

CT scan

This will show a dilated kidney and define the anatomy. It is also useful for checking for crossing vessles.

MAG-3 Scan

This will assess the function of the kidney and check if the kidney is truly blocked or not.


Treatment depends on underlying cause. Since in the majority of cases a benign cause is identified surgical correction with a procedure called pyeloplasty is done.

To find out more about Pyeloplasty Click Here.