Vesicoureteral reflux (VUR) is when urine backs up from your bladder into one or both ureters. Ureters are the tubes that connect your bladder to your kidneys.

VUR is most common in infants or young children and is rare in adults.

VUR usually doesn’t cause symptoms itself, but it increases the risk of urinary tract infections (UTIs) and kidney infections. Mild VUR often doesn’t need treatment, and many children outgrow it. Children who develop infections may need to take antibiotics, and less commonly, may need surgery.

Read on to learn everything you need to know about VUR, including symptoms, causes, and treatment options.

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Illustration by Yaja’ Mulcare

In most children, VUR doesn’t directly cause any signs or symptoms, according to a 2021 research review. The most common sign is the presence of a UTI. People with VUR commonly develop UTIs because backward flowing urine promotes the growth of bacteria.

It can be difficult to know if your child has a UTI. This is especially true with infants, who can’t communicate well.

Signs and symptoms can include:

Children with VUR are also more likely to have:

VUR is uncommon in adults. One sign in adults, according to 2018 research, is the recurrent development of kidney infections.

VUR is categorized as either primary or secondary, depending on the cause.

Most cases of VUR are primary. This means they are caused by atypical development of the valve between the ureter and bladder. When this valve doesn’t close properly, urine flows back from the bladder toward the kidneys.

VUR is categorized as secondary if it’s caused by blockages in the urinary system or issues with the nerves that allow the bladder to relax. These conditions cause pressure in the bladder that can push urine back into your ureters and toward your kidneys.

VUR is most common in infants and young children under the age of 2, according to the National Institute of Diabetes and Digestive and Kidney Diseases. It becomes less common with age. Older children and adults can also develop VUR, but it’s uncommon.

VUR also tends to run in families, per 2016 research. About 27.4 percent of children with a sibling who has VUR and 35.7 percent with a parent who has VUR develop it too.

VUR is diagnosed in females more often than males, 2019 research suggests. This is because females have higher rates of UTIs. For the same reason, VUR is more commonly diagnosed in uncircumcised males than circumcised males, researchers say.

In a 2017 study, researchers found that female infants under 6 months were 3 times more likely than male infants to develop VUR. From around the age of 21 to 24 months, however, there was an equal prevalence between sexes.

The most common complication of VUR is the development of UTIs. Most children with VUR recover without complications. However, UTIs that spread to the kidneys can lead to scarring, which is permanent damage.

Kidney scarring is most likely when VUR isn’t treated or isn’t treated quickly. If the kidneys become significantly damaged, your child can develop problems like high blood pressure and, rarely, kidney failure.

About half of people with acute kidney infections develop scarring, according to 2022 research. Up to 15 percent of people with VUR may develop kidney scarring.

About 1 in 3 children who develop a UTI with a fever have VUR. In a 1999 study of 2,000 newborns, about 1 percent had VUR. However, this research is older and additional study is needed to obtain more recent data.

The main concern of VUR is the development of UTIs or kidney infections. Treatment aims to minimize the risk of these complications.

VUR is graded on a grade scale of 1 to 5, with grade 1 being the least serious and grade 5 being the most serious.

Active surveillance

Children often outgrow VUR and don’t require treatment. About 80 percent of cases of grade 1 or 2 VUR and 50 percent of cases of grade 3 VUR resolve without treatment, according to a 2017 research review. The average age for it to go away is 5 or 6.


Your child’s doctor may recommend a continuous low dose of antibiotics or antibiotics after an infection develops.

Currently, the American Urological Association (AUA) recommends continuous antibiotic therapy for children younger than age 1 who have a history of UTIs or have grade 3 to 5 VUR without a history of UTIs.

For children under age 1 without a history of UTIs and grade 1 or 2 VUR, continuous antibiotic therapy may be considered, per the AUA.

In children older than 1 with a history of UTIs, the AUA recommends considering continuous antibiotic therapy. Watchful waiting with the prompt initiation of antibiotic therapy when a UTI develops may also be considered.

Surgery and other treatments

Healthcare professionals sometimes consider surgery when a child has repeated UTIs, especially if they have high grade VUR or kidney scarring.

Your child’s doctor may recommend a procedure called a ureteral reimplant. This surgery changes the way the ureter connects to the bladder to keep urine from backing up.

A doctor may recommend another type of procedure, where a small amount of gel is injected into the bladder near the connection of the ureter. This gel makes a bulge in the wall of your bladder that acts like a valve.

Doctors may consider circumcision for uncircumcised male infants younger than 1, according to the AUA.

A tube called a urinary catheter may be used to drain urine if your child can’t properly empty their bladder.

It’s important to visit your child’s doctor if your little one develops a UTI or if you suspect they have a UTI. These infections are usually easy to treat but require a prescription for antibiotics.

The American Academy of Pediatrics recommends that children receive a renal (kidney) and bladder ultrasound after they have their first UTI with a fever.

VUR is sometimes found before birth on a sonogram or ultrasound, but it’s most often diagnosed when children are 2 to 3 years old.

A type of X-ray called a voiding cystourethrogram can help diagnose VUR. This test takes about 30 minutes to 1 hour.

During the test:

  1. A healthcare professional will place a thin tube in your child’s urethra.
  2. They will inject a special dye through the tube until your child’s bladder is full.
  3. Your child will urinate.
  4. The healthcare professional will take X-ray images of the bladder to see if the dye enters one or both kidneys.

A urine test can be used to screen for signs of white blood cells and bacteria that suggest a UTI.

You can’t prevent VUR, but you can take steps to maximize your child’s bladder health, such as:

Your child’s doctor can help answer any questions you have about their VUR. Some questions you may want to ask include:

  • How long will my child have VUR?
  • Is medical treatment necessary?
  • Should my child take antibiotics?
  • Will my child need surgery?
  • Which treatment is best?
  • Will this condition cause my child pain?
  • How often should I follow up?

VUR is a urinary condition where urine backs up from the bladder into the ureters. It usually doesn’t directly cause symptoms but can put your child at risk of UTIs and kidney infections.

Mild cases of VUR often don’t require treatment, and children often outgrow it. More serious cases may require antibiotics or surgery.

A healthcare professional can help you decide on the best treatment option and order tests to diagnose it.