Narrowing of the ureter tube is called a ureteral stricture. Urine backs up into the kidney and causes side and back pain, sometimes kidney infections, kidney stones or kidney damage to function of the kidney.
Ureteropelvic Junction Obstruction (UPJ)
The urine flow from the kidney into the the ureter is blocked. The point of blockage is where the ureter (tube attached to kidney that drains urine to bladder) meets the collecting system or the portion of the kidney that collects the urine made by the kidney.