Hydronephrosis with ureteropelvic junction obstruction

This code represents the dilation of the renal pelvis and calyces (hydronephrosis) caused by an obstruction at the junction where the renal pelvis meets the ureter (ureteropelvic junction, or UPJ). This obstruction impedes the normal flow of urine from the kidney to the bladder, leading to urine backup and kidney swelling.

Use this code when documentation specifies hydronephrosis directly attributed to an obstruction at the ureteropelvic junction. This diagnosis is often made based on imaging studies such as ultrasound, CT, or MRI, confirming both the hydronephrosis and the UPJ obstruction. It applies when the cause of the obstruction is not specified as a calculus.

• Carefully review documentation to ensure the obstruction is specifically at the ureteropelvic junction, not elsewhere in the urinary tract.
• Distinguish this code from N13.2 if a calculus is explicitly identified as the cause of the UPJ obstruction.
• Consider any associated symptoms or underlying conditions that may require additional codes, such as pain or infection.