Urine normally flows from your kidneys down to your bladder. In children with vesicoureteral reflux (VUR), urine “backflows” or “refluxes” from the bladder back up the ureters to the kidneys.
VUR alone doesn't damage the kidneys. HOWEVER,
vesicoureteral reflux increases the risk of urinary tract infections because if there is an infection in the bladder, VUR makes it much easier for bacteria to travel up the ureters and then enter the kidneys where infection and kidney scarring can occur. Untreated VUR can lead to kidney damage. It can be diagnosed in utero, at birth, or in early childhood after repeated bladder infections. Approximately 30 to 40 percent of children who have a urinary tract infection are found to have reflux. In most cases, it is a febrile urinary tract infection (UTI), meaning the child has a high fever in addition to the bladder infection, resulting from the bacterial infection passing into the ureters and/or the kidneys.
There are two types of vesicoureteral reflux — primary and secondary. Children with primary vesicoureteral reflux are born with a defect in the valve that normally prevents urine from flowing backward from the bladder into the ureters. Secondary vesicoureteral reflux is due to a blockage, often caused by infection, in the urinary tract. There are 5 grades of reflux, with "5" being the most severe. Reflux can be unilateral (on one side) or bilateral (on both sides). In reflux of grade 3 or higher, the urine backflows into the kidney.
Children may outgrow primary vesicoureteral reflux by the time they are 5 years old. Treatment, which includes antibiotic prophylaxis or surgery or both (depending on the grade of reflux), is geared at preventing kidney damage and scarring.
If a parent or a sibling has suffered from VUR, the chances of another sibling being born with VUR have been found to be as high as 50%.
VUR is very common, up to 1 - 2% of children are diagnosed.
The following websites give more information: