In humans, the immediate result of a blockage in one ureter would be to decrease the amount of urine entering the bladder.
A condition which occurs as a consequence of blockage in one or both of the ureters is called ureteral obstruction.
Ureters are tubes, part of the urine system that carry urine from the kidneys to the bladder.
Ureteral obstructions might be due to ureteral stones, tumors, swelling of the ureter wall.. Ureteral obstruction can cause complications such as urinary tract infections and kidney damage.