Vesicoureteral Reflux

Your urinary tract is a one-way street from your kidneys down to your urethra. VUR (vesicoureteral reflux) is when your pee goes in the wrong direction, back up your ureters. It affects newborns, toddlers and children most often, but VUR usually isn’t typically painful or long-lasting, and treatment is available.


Urinary system showing pee backing up in one ureter and kidney next to a ureter and kidney that are normal.
Vesicoureteral reflux (VUR) is when pee flows up from your bladder back into your kidney. It can cause kidney infection.

What is vesicoureteral reflux (VUR)?

Vesicoureteral reflux (VUR) is a condition where pee (urine) flows in the wrong direction. Instead of flowing from your kidneys, down into your ureters and bladder where it stays until you pee, your pee flows backward from your bladder.

Your urinary tract is typically a one-way valve, with pee flowing down your urinary tract. This valve-like mechanism prevents pee from going back up into your ureters after it gets to your bladder. Typically, pee should flow like this:

  • Kidneys produce pee. Typically, you have two kidneys.
  • Two thin, muscular tubes called ureters carry pee from your kidneys to your bladder.
  • Your bladder holds or stores your pee. It can expand like a balloon.
  • Your pee leaves your body through your urethra. Your urethra is the opening your pee comes out of.

In VUR, pee flows back — or refluxes — from your bladder into one or both of your ureters and, in some cases, to one or both kidneys. It happens most often due to an issue that prevents the one-way valve from functioning as it should.

Vesicoureteral reflux (VUR) mostly affects newborns, infants and young children ages 2 and under, but older children and (rarely) adults can also have VUR.

Pee flowing the wrong way can cause bacteria to get into your child’s kidneys and cause infection. Kidney infections can cause permanent kidney damage when left untreated.

Treatment for VUR depends on the severity of your child’s symptoms, age and other factors. Mild cases may not need treatment and some children outgrow VUR. But some children need surgery or medication to treat VUR so it doesn’t cause kidney damage.

What are the types of vesicoureteral reflux?

VUR that affects only one ureter and kidney is called unilateral reflux. VUR that affects both ureters and kidneys is called a bilateral reflux.

The two types of VUR are primary and secondary:

  • Primary VUR: Most cases of VUR are primary and more commonly affect only one ureter and one kidney (unilateral reflux). With primary VUR, your child is born with a ureter that doesn’t connect into their bladder properly. The flap valve between their ureter and bladder wall doesn’t close correctly, so pee refluxes from their bladder to the ureter and, in some cases, their kidney.
  • Secondary VUR: Secondary VUR occurs when a blockage in the urinary tract causes an increase in pressure and pushes pee back up from the urethra into your child’s bladder, ureters or kidneys. The blockage could result from an abnormal fold of tissue in the urethra that keeps pee from flowing freely out of your child’s bladder. Another cause of secondary VUR might be a problem with nerves that can’t stimulate the bladder to release pee. Children with secondary VUR often have bilateral reflux (affects both ureters or both kidneys).

What are the stages of vesicoureteral reflux (VUR)?

The stages of VUR are grades and there are five of them. Five is the most severe form of VUR and one is the mildest form. The grading system is based on:

  • How far the pee backs up into the urinary tract.
  • The width of the ureter(s) or if the ureter is enlarged.

The grade breakdown is:

  • Grade one: Pee goes backward up into a ureter, but the ureter is a normal width.
  • Grade two: Pee backs up into a ureter and the kidney pelvis, which is the area where the ureter and kidney meet. Both the kidney pelvis and ureter haven’t gotten wider.
  • Grade three: The ureter(s), kidney pelvis and calyces (where pee collection begins in the bladder) are mild to moderately enlarged due to pee backing up.
  • Grade four: The ureter(s) are curved and moderately widened, and the kidney pelvis and calyces are also moderately widened because of too much pee backing up.
  • Grade five: The ureter(s) are extremely distorted and enlarged. The kidney pelvis and calyces are very large from an excessive amount of pee backing up.

How common is vesicoureteral reflux (VUR)?

About 1% to 3% of children have vesicoureteral reflux (VUR). About 75% of children with VUR are assigned female at birth (AFAB).


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Symptoms and Causes

What are the symptoms of vesicoureteral reflux (VUR)?

In many cases, a child with vesicoureteral reflux (VUR) has no symptoms. When symptoms are present, the most common is a urinary tract infection (UTI). Some estimates show that 30% to 50% of children with a UTI have VUR.

Symptoms of a UTI in a child include:

Noticing signs of UTI in an infant can be more difficult. They may show signs of fussiness or lose their typical appetite.

Is vesicoureteral reflux (VUR) painful?

No, vesicoureteral reflux (VUR) isn’t painful. But if there is a UTI, that can come with pain during urination and pain in the kidney/abdominal region.

What causes vesicoureteral reflux (VUR)?

The two types of vesicoureteral reflux (VUR), primary and secondary, have different causes.

  • Primary VUR: The most common cause of primary VUR in children is an irregularity with the flap valve between your child’s ureter and bladder. It doesn’t close efficiently, so pee backs up toward their kidney instead of flowing downward. As your child grows, the organs and structures mature, and the valve may close correctly and primary VUR may improve.
  • Secondary VUR: The most common cause of secondary VUR is a blockage by tissue or narrowing in the bladder neck or urethra. These problems cause pee to back up into the urinary tract instead of exiting down through the urethra. Your child may also have nerves to the bladder that don’t work as well as they should. That problem can keep their bladder from contracting and relaxing normally, which means their pee doesn’t release as it should. Bilateral VUR is more common with secondary VUR.

What are the risk factors for this condition?

Risk factors for VUR include:

  • Genetics: VUR appears to run in biological families. If one child in a family has VUR, there’s a little more than 1 in 4 chance that their sibling will also have the condition. If a parent had VUR, there is a 1 in 3 chance that their child will also have VUR.
  • Birth disorders: Children who are born with irregular kidneys or urinary tracts are more likely to have VUR.
  • Bladder and bowel dysfunction (BBD): Children with BBD have problems with regular bowel movements and peeing, typically due to muscle or nerve issues.
  • Race and sex: White children assigned female at birth (AFAB) are more likely to have VUR.


What are the complications of vesicoureteral reflux (VUR)?

Complications of vesicoureteral reflux (VUR) in children include:

Most children with VUR recover without long-term complications.

What causes vesicoureteral reflux (VUR) in adults?

Adults with vesicoureteral reflux (VUR) typically have benign prostate hyperplasianeurogenic bladder or they had surgery near their ureters.


Can vesicoureteral reflux cause kidney stones?

Yes. It can also cause kidney stones and stones in other parts of your urinary tract like your bladder.

Is vesicoureteral reflux life-threatening?

Vesicoureteral reflux (VUR) itself isn’t life-threatening. However, VUR can lead to recurrent urinary tract infections (UTIs), which can cause kidney scarring and then worsen into renal hypertension (high blood pressure from kidney disease) and kidney disease. End-stage kidney disease requires dialysis and/or a kidney transplant.

Diagnosis and Tests

How is vesicoureteral reflux (VUR) diagnosed?

Pediatric nephrologists and pediatric urologists are medical doctors who focus on kidney and urinary tract conditions. It’s likely your pediatrician will refer you to one or both of these specialists for your child’s care.

They may order the following tests to diagnose vesicoureteral reflux (VUR):

  • Voiding cystourethrogram (VCUG): VCUG is an X-ray image of the bladder and urethra taken before, during and after urination. A small catheter is placed into the urethra and is used to fill your child’s bladder with a special dye that can be seen by X-ray. The X-rays show if urine is flowing backward from their bladder into the ureters. A provider performs this procedure in their office, an outpatient center or a hospital. Anesthesia isn’t necessary, but sedation may help some children.
  • Ultrasound: This safe and painless imaging technique uses sound waves to create images of your child’s entire urinary tract, including their kidneys and bladder. The study occurs in a healthcare provider’s office, outpatient center or a hospital. A provider may use an ultrasound before a VCUG or RNC if you or your healthcare provider want to avoid exposure to X-ray radiation or radioactive material. A fetal ultrasound can also show signs of VUR (like swollen kidneys), which means a person can learn their child may have VUR during pregnancy.
  • Dimercaptosuccinic acid (DMSA) scan: This imaging test reveals if scars developed in your child’s kidney due to kidney UTIs.
  • Radionuclide cystogram (RNC): RNC is a type of nuclear scan that involves placing radioactive material into your child’s bladder. A scanner then detects the radioactive material as your child urinates or after their bladder is empty. The procedure happens in a healthcare provider’s office, outpatient center or a hospital by a specially trained technician, and the images are interpreted by a radiologist. Your child won’t need anesthesia, but sedation may help some children. RNC is more sensitive than VCUG but doesn’t provide as much detail of the bladder anatomy.

What other tests do children with vesicoureteral reflux (VUR) need?

If your child receives a vesicoureteral reflux (VUR) diagnosis, they should have the following tests regularly:

  • Blood pressure checks: Kidney problems put a child at higher risk for high blood pressure.
  • Blood tests: High levels of protein or creatinine are signs of kidney damage.
  • Urine tests and culture: Protein in pee is a sign of kidney damage and bacteria in pee is a sign of infection.

Your child’s healthcare provider may also evaluate them for bladder and bowel dysfunction (BBD). Symptoms of bowel and bladder problems include:

Children who have VUR along with any BBD symptoms are at greater risk of kidney damage due to infection.

Management and Treatment

How is vesicoureteral reflux (VUR) managed?

Managing VUR requires the help of a healthcare provider. Treatment options depend on your child’s age, symptoms, type of VUR and its severity. Treatments include antibiotics and other medications, an injectable dissolvable bulking agent, short-term catheterization and surgery. You and your pediatrician and specialists will discuss these treatment options and make the best choice for your child’s VUR.

Primary VUR treatment

Primary VUR may improve with age (typically by age 5). Sometimes, a wait-and-see approach works. Other times, surgery or medications are necessary.


As your child gets older and their urinary tract anatomy grows and matures, primary VUR will often improve. Until then, your healthcare provider will prescribe an antibiotic to treat or prevent a urinary tract infection (UTI).

Use of long-term antibiotics for the prevention of UTI is somewhat controversial. Extended use of antibiotics can lead to antibiotic resistance. The American Academy of Pediatrics (AAP) recommends preventive antibiotics mostly for children with higher grades of VUR (while waiting to see if they outgrow VUR).


Healthcare providers use several different surgical methods for primary VUR. The goal of surgery is to fix the connection point (one-way valve mechanism) between the bladder and ureters to prevent pee from flowing backward.

Ureteral reimplant

The gold standard procedure for surgical correction of VUR is called a ureteral reimplant. The goal of the reimplant is to create a flap-valve mechanism, which means re-routing the ureter in the bladder wall with an appropriate length of tunnel so urine doesn’t reflux back up into the ureter. Your child’s surgeon can perform this procedure with an open surgery (incision in your child’s abdomen) or laparoscopically. Your child’s surgeon can discuss the benefits and risks of each method with you, as well as possible side effects. Surgery requires general anesthesia, and possibly, a short hospital stay.

Injectable bulking agent

Another type of procedure for primary VUR is the use of hyaluronic acid/dextranome (Deflux®), a gel-like liquid. Your child’s provider injects a small amount into your child’s bladder wall near the opening of the ureter. This injection creates a bulge in the tissue and acts like a valve that makes it harder for pee to flow backward. It’s an outpatient procedure (your child goes home the same day), but still requires general anesthesia. Your child’s provider can discuss the risks and benefits of this type of treatment with you.

Secondary vesicoureteral reflux (VUR) treatment

Healthcare providers treat secondary vesicoureteral reflux (VUR) by removing the blockage or improving how the bladder empties. Treatment may include:

  • Surgery to remove a blockage or correct an irregularly shaped bladder or ureter.
  • Antibiotics to prevent or treat a UTI.
  • Intermittent catheterization (draining the bladder by inserting a thin tube through the urethra to the bladder).
  • Bladder muscle medication.


Can VUR be prevented?

There isn’t a known way to prevent vesicoureteral reflux (VUR) — not with food, lifestyle changes or medication. But there are steps you can take to improve your child’s overall urinary tract health. Make sure your child:

  • Drinks enough water.
  • Gets their diaper changed immediately after they poop and pee.
  • Pees regularly and avoids “holding it.”
  • Receives treatment for constipation and urinary or fecal incontinence as soon as possible.

Help your child to be healthy by encouraging exercise and making sure meals are balanced and nutritious.

Outlook / Prognosis

What can I expect if my child has vesicoureteral reflux (VUR)?

If your child receives a VUR diagnosis, work closely with their healthcare team on a treatment plan that works for your family. Managing a condition like VUR can have an effect on you and other caregivers. Be sure to discuss your concerns with your child’s healthcare team. The good news is that VUR is highly treatable and most children don’t have long-term effects from it.

How long will my child have VUR?

Your child should have vesicoureteral reflux (VUR) for less than a year, but an exact timeline depends on your child’s condition. Your child’s healthcare provider may recommend a wait-and-see approach or they may suggest surgery if they see severe VUR or kidney damage on imaging tests.

Can you grow out of vesicoureteral reflux?

Yes. It’s possible for your child to grow out of VUR, especially if they have a lower grade (one or two) of primary VUR. Children may outgrow this type within a few years.

Can my child go to school with vesicoureteral reflux (VUR)?

It depends on the severity of their symptoms. Remember, VUR itself isn’t disruptive to your child’s day-to-day living, but UTIs can be. Although not contagious, your child may be in pain or have problems with constipation or incontinence. Meet with your healthcare provider to discuss options for returning to school and participating in playdates.

Living With

When should I see my healthcare provider about vesicoureteral reflux (VUR)?

See your child’s pediatrician if you suspect a UTI, as this is often the first sign of VUR. Other signs like urinary incontinence, unexplained fever or painful urination can also suggest VUR. Your pediatrician may send you to a specialist if they suspect VUR.

What questions should I ask my healthcare provider?

Have a conversation with your child’s healthcare provider to get answers to all of your questions about vesicoureteral reflux (VUR). Some questions you can ask include:

  • Will my child’s primary VUR get better without treatment?
  • Does my child also have kidney problems?
  • Should I see a specialist?
  • How will you treat my child’s VUR?
  • What are the consequences of untreated VUR?
  • What can I do at home to improve my child’s condition?
  • Will this condition cause my child pain?
  • How do I know if VUR is affecting other organs or bodily functions?
  • How can I prevent a urinary tract infection?
  • Should my other children be checked for VUR?

A note from Cleveland Clinic

Remember that vesicoureteral reflux (VUR) isn’t usually painful or life-threatening. It’s manageable and treatments are usually successful. There’s no way to prevent it, but make sure to have your child drink plenty of water, get exercise and eat nutritious meals to maintain their overall health. Rely on your healthcare provider’s expertise. They’ll help diagnose and treat your child’s VUR. Don’t hesitate to contact them with questions and concerns, and be open and honest about your child’s symptoms, even if they’re awkward to talk about.

Medically Reviewed

Last reviewed on 02/19/2024.

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