Vesicoureteral reflux (VUR) is a medical condition where urine flows in a reverse direction, from the bladder back into the ureters and possibly into the kidneys. This condition is also known as ureteral reflux or urinary reflux. VUR is a common problem in young children, and it can lead to urinary tract infections, kidney damage, and other complications. There are different grades of severity of VUR, ranging from grade I, which is mild reflux, to grade V, which is the most serious form. Other synonyms for VUR include reflux nephropathy, pyelonephritis, and obstructive uropathy. Early detection and treatment are crucial to prevent long-term damage.