What is Vesicoureteral Reflux?

Medically Reviewed by Dan Brennan, MD on May 23, 2023
5 min read

Vesicoureteral reflux (VUR) is when the flow of urine goes the wrong way. This condition is more common among infants and young children.

Urine, which is the liquid waste product from your body, normally flows one way. It travels down from the kidneys, then into tubes called the ureters and gets stored in your bladder. You release the urine out of your bladder when you pee.

When you have VUR, the urine in your bladder goes back up to the ureter and the kidneys. This could cause infections and damage your kidneys.

VUR affects up to 1.8% of children. Although most are able to grow out of this condition, people who have severe cases may need surgery to protect their kidneys.

VUR can also affect adults and older children.

A flap valve is located where the ureter joins with the bladder. Usually, the valve allows only a one-way flow of urine from the ureters to the bladder. But when that flap valve doesn’t work right, this allows the backflow of urine. This can affect one or both ureters. You might hear your doctor or nurse call this “primary vesicoureteral reflux.”

In what’s known as “secondary vesicoureteral reflux,” there’s a blockage at the bladder that causes urine to push back into the ureters.

Your chances of getting VUR are higher with the following:

Birth defect. This is the issue in most primary VUR cases. A child could have a short flap valve that doesn’t work.

Genes. Your more likely to get VUR if you’re parents or siblings have had the condition. But no specific genes have been found responsible for VUR.

Abnormal bladder function. Children who have nerve or spinal cord problems such as spina bifida (a birth defect of the spine) have a higher chance of VUR.

Urinary abnormalities. Children with problems in their urinary system are more likely to get this condition. Some of those problems include:

  • Bladder exstrophy (birth defect affecting urinary tracts)
  • Uterocele (defect in the ureters)
  • Ureter duplication (an extra ureter exists for one kidney)

Bladder and bowel problems. Children with bathroom accidents, frequent urination or constipation are more likely to have VUR.

Many children with VUR don’t have symptoms. But when they do, the most common one is a urinary tract infection (UTI) caused by bacteria. UTIs might not always come with symptoms, but when they do, they could include:

  • Strong urge to pee
  • Pain or burning while urinating
  • Blood in urine or cloudy, stinky urine
  • Peeing small amounts
  • Fever
  • Sudden, frequent urination or wetting
  • Abdominal pain

If you see these UTI symptoms in your child, contact your doctor. If your child has a rectal temperature of 100.4 F or fever of 102 F, call your doctor at once.

Other symptoms for VUR may include:

VUR can be detected before birth by an ultrasound, which uses sound waves to provide an image of the inside of your body.

One or more of these tests can also be used:

  • Voiding cystourethogram (VCUG). During this exam, a doctor uses a thin, plastic tube to inject a fluid with an X-ray dye into your bladder. Then an X-ray machine takes a video while you pee to see whether the fluid goes backward from the bladder to reach one or both kidneys. Children may become upset during this test, so it can be done with medicines that help keep them calm.
  • Radionuclide cystogram (RNC). This process is similar to the voiding cystourethogram, except the contrasting dye is a radioactive material that is detected by a nuclear scan.
  • Abdominal ultrasound. Safe, painless sound waves bounce off organs to create an image of the entire urinary tract. This could be used to find out how your kidneys are doing, including whether there are scars or other problems.
  • Urodynamics. This tests the bladder to see how well it’s collecting, holding, and releasing urine. It’s used to see whether problems in the bladder are part of your VUR problem.
  • Blood test. This exam looks for waste products that are usually removed from the blood by your kidneys. The blood test gives an idea of how your kidneys are doing.
  • Urine test. This tests for proteins or blood in your pee, which could indicate whether you have a UTI.

If you or your child have VUR, your doctor will give you a number score that ranges from 1 to 3, or 1 to 5, depending on what kind of test was taken. The higher the number, the more severe the VUR.

Your treatment will depend on that score as well as your overall health. The lower the score is, the more likely the reflux will go away on its own.

This is why your doctor may take a wait-and-see approach. Children often outgrow VUR as the valve between their bladder and ureter gets longer with age.

Treatment could include:

  • Antibiotics. These are used to treat UTIs and also to keep the infection from moving to the kidneys.
  • Deflux. This gel-like liquid is injected in the bladder near the opening of the ureter. The injection creates a bulge that makes it harder for urine to flow back up the ureter.
  • Surgery. This is used in severe cases when things are not improving or the kidneys are being damaged. Surgery can be used to repair the problems in the valve between the bladder and ureter.

If you’re a parent of a child with VUR, try to get them to use the bathroom regularly. Other tips include:

  • Make sure your child takes the prescribed antibiotics, even if they’re used to prevent UTIs.
  • Get your child to drink more water, as it helps flush out bacteria from the UTI. Avoid juices and soft drinks as they can irritate the bladder.
  • Place a warm blanket or towel over your child’s abdomen to ease pain or pressure.