Vesicoureteral reflux (VUR) is the backward flow of urine. The urine flows from the bladder back into the kidney.

Urine normally flows from the kidneys. It passes through tubes called ureters. It then flows into the bladder. Each ureter connects to the bladder in a way that prevents urine from flowing back up the ureter. It is similar to a one-way valve. When this does not work properly, or if the ureters do not extend far enough into the bladder, urine may flow back up to the kidney. If the urine contains bacteria, the kidney may become infected. The backup can also put extra pressure on the kidney. This can cause kidney damage.

This is a potentially serious condition that requires care from your doctor. The sooner VUR is treated, the better the outcome. If you suspect you or your child has this condition, contact your doctor immediately.

Anatomy of the Urinary System

© 2009 Nucleus Medical Art, Inc.


This condition may be caused by:

  • A problem in the way the ureter inserts into the bladder
  • A ureter that does not extend far enough into the bladder
  • Bladder outlet obstruction (eg, blockage of urine flow from an enlarged prostate gland)
  • Neurogenic bladder (loss of normal bladder function due to damaged nerves reaching the bladder)
  • Temporary swelling after kidney transplant

Risk Factors

The following factors increase your chance of developing VUR:

  • Family history
  • Congenital abnormalities of the urinary tract
  • Birth defects that affect the spinal cord, such as spina bifida
  • Tumors in the spinal cord or pelvis
  • Spinal cord injury


In most cases, VUR has no obvious symptoms or signs. It is often found after a kidney infection is diagnosed.

A prenatal ultrasound may show a swelling of the kidneys. This is called hydronephrosis . It may indicate VUR.


Your doctor will ask about your symptoms and medical history. A physical exam will be done. Tests may include the following:

  • Blood tests—to assess how well the kidneys are functioning
  • Urine tests—to look for evidence of an infection or damage to the kidneys
  • Ultrasound—a test that uses sound waves to examine the kidney and bladder
  • CT scan —a type of x-ray that uses computers to make pictures of structures inside the body
  • Voiding cystourethrogram (VCUG)—a liquid that can be seen on x-rays is placed in the bladder through a catheter; x-rays are taken when the bladder is filled and when urinating.
  • Intravenous pyelogram—a liquid that can be seen on x-rays is injected into a vein; x-ray images are taken as the substance travels from the blood into the kidneys and bladder,
  • Nuclear scans—a variety of tests using radioactive materials injected into a vein or the bladder to show how well the urinary system is working
In rare cases, high blood pressure may be an indication of kidney damage.


The goal for treatment of VUR is to prevent any permanent kidney damage. Treatment options include the following:


Most cases of VUR in children clear up on their own. The problems may clear as the ureters develop. Observation may include:

  • Regular urine cultures
  • Antibiotics—children at risk of infections or who have had many infections are often placed on low dose, daily antibiotics
  • Annual check-ups on kidney functions
Children are advised to stay well hydrated. They should also frequently empty their bladders.


Endoscopic injection into the ureter

This procedure is a minimally invasive surgery. It is done to correct the reflux. A chemical is injected where the ureter inserts into the bladder. This will prevent urine from going back up the ureter. This procedure is done through a small tube called a cystoscope .

Ureteral reimplantation

A surgery that repositions the ureters in the bladder.


VUR can not be prevented. However, further complications can be avoided:

  • Seek prompt treatment for bladder or kidney infections.
  • This is particularly true if you have a neurogenic bladder.