An Overview of Vesicoureteral Reflux

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Typically, your urine flows downward through your urinary tract from your kidneys through your ureters (ducts that connect the kidneys to the bladder) to your bladder. With vesicoureteral reflux (VUR), some of the urine flows in the opposite direction—back from your bladder to your ureter (one or both) and up to your kidneys.

When this happens, bacteria can pass from your bladder to your kidneys, possibly causing a kidney infection that may then lead to kidney damage and scarring. Further, excessive scarring of the kidney(s) can lead to kidney failure and high blood pressure.

At the point where each ureter joins the bladder, there is a valve that keeps the urine flowing in just one direction and prevents it from flowing backward. When this valve isn’t working properly, urine can flow back upwards to the kidneys.

Infants, toddlers, and young children are the most likely to have vesicoureteral reflux, and as such it’s uncommon in older children and adults.

VUR can vary in severity, and healthcare providers usually grade them from grade 1 (the mildest form) through to grade 5 (the most severe form).

vesicoureteral reflux grades
Verywell / JR Bee


The most common symptoms of VUR are urinary tract infections (UTIs). This is because as the urine flows backward, it becomes easier for bacteria to grow in your child’s urinary tract system. The urinary tract infection may involve the kidneys or bladder, or both.

Common Symptoms of UTIs

  • Burning feeling when urinating
  • Blood when urinating
  • A strong and continuous need to urinate
  • Pain in the abdomen or side of the torso
  • Fever, especially if it's unexplained
  • Fussiness and poor feeding in babies

There's a 30-40% chance that if your child has a UTI along with a fever, they have VUR.

Other symptoms of VUR include:

  • Bedwetting incidents
  • Incontinence, the inability to fully hold urine in
  • Diarrhea
  • Constipation
  • Irritability
  • Feeling sick or vomiting
  • Poor weight gain in babies

Another symptom of VUR which can be diagnosed via sonogram while your baby is still in the womb is hydronephrosis—swelling or stretching of the kidneys. In rare cases, hypertension may be a symptom of VUR too.

Often enough though, if your child has VUR, they may not show any symptoms at all.


The cause of VUR depends on the type it is: primary or secondary.

Primary VUR

Primary VUR is the most common kind. This type of reflux is caused by a congenital defect—abnormal ureter(s) present from birth. With this type, the valve that stops the backward flow of urine does not close properly. In some cases, referred to as unilateral reflux, only one ureter and kidney are affected.

A lot of times, primary VUR goes away on its own or gets better. This is because as humans grow older, the ureters mature and strengthen. This, in turn, gets the valve to function better, leading to an end of the reflux.

Secondary VUR

Secondary VUR Risk Factors
Verywell / JR Bee

Secondary VUR can be caused by many factors, which have the effect of not letting the bladder empty out well. A blockage of the bladder or ureter can cause urine to flow back upwards to the kidneys.

In other cases, secondary VUR is caused by nerve problems that do not allow the bladder to function properly enough to let urine flow out normally. In secondary VUR, it is more likely that the ureters and kidneys are affected. This is also known as bilateral reflux.

Additionally, there are certain factors that make your child more likely to have VUR, including:

  • Sex: Girls are more likely to have VUR than boys, except when the VUR is already present at birth, in which case, it's seen more in boys.
  • Family history: Primary vesicoureteral reflux is linked to genetics, although to date no specific gene has been identified as its cause. A child is more likely to have it if any of the parents or siblings have it. This is why it’s important to get children who have a parent or sibling with VUR screened by a healthcare provider.
  • Habits: Abnormal urination habits such as holding in pee unnecessarily, also known as bladder and bowel dysfunction.
  • Age: Really young children, below the age of 2, are more likely to have VUR than their older counterparts.
  • Other birth defects: Children with conditions like spina bifida which affect the nerves and spinal cord.
  • Abnormalities: The presence of urinary tract abnormalities like ureterocele and ureteral duplication can also make a child more likely to have VUR.


To diagnose VUR, healthcare providers can make use of different tests. But before they order a test, your practitioner will consider the age of your child, family history of VUR (if any), and the symptoms your child has been experiencing. If there’s probable cause to believe VUR is present, your healthcare provider will order one or more of the following tests:

Voiding Cystourethrogram

This test makes use of X-ray to get images of the bladder. During it, a catheter is inserted into the urethra and through this catheter, contrast dye is injected into the bladder until it's filled up. Your child will then be asked to urinate. Pictures of the bladder will be taken before, during, and after this urination. This way, the healthcare provider is able to see if the urine flows backward into the ureters.

Voiding cystourethrogram (VCUG) uses a small amount of radiation. Your child may feel some discomfort while the catheter is being inserted, and subsequently when peeing after it has been taken out. Speak to your healthcare provider (typically a pediatric urologist) about pain management options.

Abdominal Ultrasound

Also known as sonography, an abdominal ultrasound allows healthcare providers to look into the body but without the attendant radiation that comes with an X-ray. In an abdominal ultrasound, images of your child’s entire urinary tract system will be obtained. The kidneys will be evaluated to see if there’s any scarring or change in size (swelling/dilation). Additionally, any abnormalities with the bladder or ureters can also be seen via ultrasound. The healthcare provider may also use it to check for complications of UTIs if your child has just had one.

The procedure is completely painless. It simply involves the use of a gel which is spread over the abdomen and a probe (transducer) which is waved over and around the abdomen and back. Because ultrasounds are often used to monitor the progress of a baby in the womb, the presence of swollen kidneys in your fetus can be used to diagnose primary VUR before birth.

Radionuclide Cystogram

This test is very similar to the voiding cystourethrogram but a different fluid is filled into the blader and it involves less radiation exposure. It can be used for the initial diagnosis of VUR but most healthcare providers prefer the VCUG because the radionuclide cystogram shows less anatomical details than the VCUG. It is most often used after a VCUG has been used in order to continuously monitor and evaluate the VUR and determine whether it has resolved itself or not.

VUR Grades

During diagnosis, the healthcare provider will determine the grade of the VUR. The features of the different grades of VUR are:

  • Grade 1: The urine goes back up (refluxes) into the ureter only.
  • Grade 2: The urine refluxes into not just the ureter but to the kidney too. There’s no swelling (hydronephrosis) present.
  • Grade 3: The urine refluxes into the ureter and kidney, and there’s mild swelling present.
  • Grade 4: The urine refluxes into the ureter and kidney and there’s moderate swelling present.
  • Grade 5: The urine refluxes into the ureter and kidney and there’s severe swelling, along with twisting of the ureter.

The healthcare provider may order a urinalysis and/or a urine culture to check for and diagnose a UTI. Blood tests may also be done to measure your child's kidney function


The treatment option your healthcare provider will recommend you pursue will depend on the type and severity of VUR your child has.

Primary VUR

In most cases, Primary VUR will resolve on its own after a couple of years. In situations like this, the healthcare provider will merely prescribe antibiotics to treat any UTIs. In some cases, the practitioner may put your child on a long-term daily antibiotic use (antibiotic prophylaxis) to prevent UTIs. This is done to make sure that your child does not develop any kidney infection that could lead to scarring or damage. The healthcare provider will also recommend that your child come in for a cystogram every year or two to check the status of the reflux.

If your child’s primary VUR is severe or is accompanied by frequent UTIs, the healthcare provider may recommend surgery. This is especially so if your child has renal scarring and the reflux isn’t showing any signs of getting better.

Secondary VUR

With secondary VUR, the particular cause of it will determine what treatment option is to be pursued.

  • If the secondary VUR is caused by a blockage, the healthcare provider may decide to surgically remove the blockage.
  • If it’s caused by an abnormality of the bladder or ureter, the healthcare provider may decide to perform surgery to correct the defect.
  • Antibiotics to prevent or treat UTIs may be prescribed by the healthcare provider.
  • In other cases, a catheter may also be used to drain the ureter periodically.

Types of Surgery Used to Treat VUR

If your healthcare provider has determined that surgery is the best course of treatment for the VUR, here are the surgical options available:

  • Open surgery: The surgeon fixes the defective valve or creates a new one through an incision in the lower belly. Open surgery is also used to remove a blockage at the ureter or bladder, if any. In very severe cases, the surgeon may also, through this process, remove a scarred kidney or ureter.
  • Ureteral reimplantation surgery: This is a type of open surgery that is used to correct an abnormally positioned ureter. In it, an incision is made in the lower abdomen, through which the surgeon will change the position of the ureters at the point where they join with the bladder, to prevent the backward flow of urine up to the kidneys. This surgery is performed under general anesthesia (that is, your child will be sound asleep throughout the procedure). Your child will likely be required to spend a few days in the hospital afterward.
  • Endoscopic surgery/treatment: The healthcare provider may also create a sort of makeshift valve for your child with a bulking injection. This procedure involves inserting a cystoscope into the urethral opening to be able to see into the bladder. Then a gel-like liquid called Deflux is injected into the ureter near its opening. This gel-like substance then forms a bulge there and makes it harder for urine to flow back upwards. General anesthesia is used for this procedure, but its mostly outpatient and your child can return home with you that same day. It has a very high success rate for those with mild to moderate VUR.

Coping With VUR

There are certain things you should do to manage your child’s VUR properly at home:

  • Encourage good urinary habits in your child, especially the use of the restroom regularly.
  • If the healthcare provider has prescribed antibiotics, either for treatment or prevention, you should ensure that your child takes all the pills, and completes the dosage (if applicable).
  • Encourage your child to drink plenty of water and fluids, as this may help to flush out bacteria.
  • Follow any additional instructions the healthcare provider has given you for your child.

A Word From Verywell

It’s perfectly normal to feel fearful or worried if your child has been diagnosed with VUR, especially if it turns out to be a more severe form of it. Accordingly, you should go ahead to extensively discuss the treatment options available with the healthcare provider. This is very important as every child is different, and what’s suitable for the next child may not be for yours. On the other hand, If your child has been diagnosed with mild primary VUR and the practitioner has expressed confidence that it will resolve on its own, you should still make sure your child attends the check-ups your healthcare provider will have scheduled.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

By Tolu Ajiboye
Tolu Ajiboye is a health writer who works with medical, wellness, biotech, and other healthcare technology companies.