Vesicoureteral reflux

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at November 17, 2016
StartDiseasesVesicoureteral reflux

Vesicoureteral reflux (VUR) occurs when urine flows backwards from the bladder to the kidneys. Vesicoureteral reflux can be primary or secondary in nature and is often associated with urinary tract infections. The condition most often appears in infants and children. While VUR can resolve on its own, treatment is required for severe cases. 


Definition & Facts

Urine usually flows down from the kidneys to the bladder. However, in vesicoureteral reflux, urine flows backwards from the bladder up through the ureters (the tubes that connect the kidneys and bladder) to the kidneys.

VUR can be primary or secondary in nature. Children with primary VUR are born with a defect in the valve that normally inhibits urine from traveling backward from the bladder to the kidneys. Primary vesicoureteral reflux is the most common type of the condition, and it is usually diagnosed shortly after birth. 

Secondary vesicoureteral reflux is caused by an obstruction in the bladder or urethra. This obstruction causes urine to flow backward from the bladder to the kidneys and is most often related to recurrent urinary tract infections, which may lead to the swelling of a ureter. Approximately one-third of children who have a urinary tract infection (UTI) have vesicoureteral reflux. Secondary VUR can occur at any age. 

Symptoms & Complaints

Urinary tract infections may not produce any noticeable signs or symptoms and can be challenging to diagnose in children. Most people with a urinary tract infection will experience some symptoms, however. A strong, persistent urge to urinate, fever, a burning sensation while urinating, hesitating to urinate or holding urine to avoid the burning sensation, and passing small amounts of urine frequently are all symptoms of urinary tract infections.

A child with a urinary tract infection may also have blood in his urine or cloudy, strong-smelling urine as well. Sometimes UTIs present with non-specific symptoms in infants and children. Other signs of UTIs in infants and children include an unexplained fever, loss of appetite, diarrhea, and irritability

Untreated UTIs can lead to some serious complications. Untreated urinary tract infections can lead to kidney infections. When the kidneys remain infected, they can become scarred over time. Extensive kidney scarring may lead to high blood pressure and kidney failure.

Older children who have untreated vesicoureteral reflux may also have other symptoms. Protein in the urine, constipation or bowel incontinence, and bedwetting are other signs that a child has VUR. 


Certain children are at increased risk for developing vesicoureteral reflux. Girls have double the risk of boys for developing secondary VUR while boys are more likely than girls to develop primary vesicoureteral reflux. White children tend to develop the condition more often than children of other races.

Additionally, infants and children up to one year of age are more likely to have the condition than older children. A family history of vesicoureteral reflux also puts a child at higher risk of having the condition. A child is more likely to have the condition if she has a parent or sibling who also has suffered from vesicoureteral reflux. 

Diagnosis & Tests

A physician can utilize a number of tests to determine if a child has vesicoureteral reflux. A urinalysis, the analysis of a urine sample, can tell a physician if a child has a urinary tract infection. However, other tests are needed to determine whether VUR is also present.

An ultrasound utilizes high-frequency sound waves to creates images of the kidneys and bladder. Ultrasounds can find bladder and kidney abnormalities. Ultrasounds are also typically used during pregnancy to monitor a baby's development. Sometimes an ultrasound shows swollen kidneys in a baby, indicating primary vesicoureteral reflux. 

A voiding cystourethrogram (VCUG) may also be helpful in diagnosing VUR. A VCUG takes X-rays of the bladder when it's full and while it is emptying to detect abnormalities. A catheter (a thin, flexible tube) is inserted into the bladder through the urethra while the child lies on his back on an X-ray table.

A contrast dye is injected into the bladder once the catheter is in place. The bladder will be subjected to an X-ray in a number of positions before the catheter is removed. X-rays are then taken of the bladder and urethra as the child urinates to determine if his urinary tract is functioning properly.

A physician may also order a radionuclide cystogram to help in the diagnostic process. A radionuclide cystogram is a similar procedure to that of a VCUG. However, in a radionuclide cystogram, a radioactive tracer is injected into the bladder through the catheter. The X-rays detect the radioactive tracer and show whether a child's urinary tract is functioning properly. 

Physicians grade vesicoureteral reflux based on the condition's severity. In the mildest cases (Grade I), urine only backs up to the ureter. In the most severe cases (Grade V), twisting of the ureter and severe kidney swelling are present. 

Treatment & Therapy

Children who have mild cases of primary vesicoureteral reflux may eventually outgrow the condition and may not need treatment. In these cases, a physician may recommend a, “wait and see” approach to a parent.

In more severe cases of vesicoureteral reflux, treatment is required. Antibiotics are utilized in the treatment of urinary tract infections to prevent them from spreading to the kidneys. A physician may choose to prescribe a low dose of antibiotics on a long-term basis to prevent infections for a child with vesicourteral reflux. The physician may also do regular urinalyses to detect breakthrough infections. Ultrasounds and X-rays may be utilized to determine if a child has outgrown vesicourteral reflux as well.

Encouraging a child with a urinary tract infection to drink plenty of water is also important. Water dilutes urine and may help flush bacteria out of the body. Parents should avoid giving children with urinary tract infections juices and soft drinks that contain citrus because they may irritate the bladder and aggravate the urgent or frequent need to urinate. 

Surgery is another treatment option for severe cases of vesicoureteral reflux. During surgery, the surgeon repairs the defect in the functional valve between each affected ureter and the bladder. The surgery ensures that the valve can close properly and prevent urine from traveling backward into the kidneys. 

Prevention & Prophylaxis

There is no way to prevent primary vesicoureteral reflux. Secondary vesicoureteral reflux is sometimes associated with recurrent urinary tract infections, and there are ways in which parents can help children prevent these infections.

Encouraging children to drink a lot of water helps prevent UTIs. Parents should also teach their children to wipe from front to back after urinating and defecating. Wiping from front to back after urinating and defecating helps prevent bacteria in the anal region from spreading to the urethra and vagina

Vesicoureteral reflux is a condition in which urine travels backwards up the ureters from the bladder to the kidneys. The condition can be congenital or associated with urinary tract infections. While some children may outgrow the condition, others will need treatment to help correct the defective valve, allowing it to close properly and prevent urine from traveling backwards into the kidneys.