What is Vesicoureteral Reflux?
Male Urinary Tract
Female Urinary Tract
Normally, urine flows one way, down from the kidneys, through tubes called ureters, to the bladder. But what happens when urine flows from the bladder back into the ureters? This is called vesicoureteral reflux.
With vesicoureteral reflux, urine flows backward from the bladder, up the ureter to the kidney. It may happen in one or both ureters. When the "flap valve" doesn’t work and lets urine flow backward, bacteria from the bladder can enter the kidney. This may cause a kidney infection that can cause kidney damage.
When the flow of urine back up the ureters is more severe, the ureters and kidneys become large and twisted. More severe reflux is tied to a greater risk of kidney damage if there is an infection present.
How Does the Urinary Tract Work?
Urine is made when blood is filtered by the kidneys. Urine flows from the kidneys down through the ureters and into the bladder. This one-way flow is usually maintained by a “flap valve” where the ureter joins the bladder. This keeps urine from backing up into the kidney.