Vesicoureteral Reflux – Symptoms and Causes

Overview

Vesicoureteral reflux occurs when urine travels backward from the bladder up into the ureters. The ureters are the tubes connecting the kidneys to the bladder. Normally, urine should only flow downward from the kidneys to the bladder.

This condition primarily affects infants and children. Some are born with it due to structural problems in their ureters, while others develop it later because their bladder doesn’t empty completely.

Many children naturally outgrow vesicoureteral reflux as their urinary system develops. Others need medical intervention.

Signs and Symptoms

People with vesicoureteral reflux often show symptoms because of a urinary tract infection (UTI). While not everyone experiences symptoms, most people notice some changes.

Common symptoms include:

• A strong urge to urinate that won’t go away
• A burning feeling during urination
• A frequent need to pass small amounts of urine
• Urine that looks cloudy
• Fever
• Pain in the stomach, side, or groin area

Babies and young children can’t explain their symptoms, but they might show:

• Unexplained fever
• Poor appetite
• Unusual fussiness or irritability

If left untreated as children grow, vesicoureteral reflux may lead to:

• Bedwetting
• Constipation or bowel control problems
• High blood pressure
• Protein appearing in urine
• Frequent or urgent urination
• Accidental urine leakage

Another sign is swelling in one or both kidneys, called hydronephrosis. This happens when urine backs up into the kidneys. Doctors can often spot this swelling before birth using ultrasound imaging.

When to Call a Doctor

Contact a healthcare provider immediately if your child shows any UTI symptoms such as:

• Strong, ongoing urge to urinate
• Burning pain while urinating
• Pain in the stomach, side, or groin
• Upset stomach or vomiting

For fever in children, call a doctor if:

• Your baby is under 3 months with a rectal temperature of 100.4°F (38°C) or higher. Note: Babies under 2 months may need emergency care
• Your child is 3 months or older with a fever of 100.4°F (38°C) or higher that lasts more than 24 hours without other symptoms
• Your child has fever along with poor eating, significant mood changes, or appears very ill

Early medical attention is important to prevent complications and protect kidney function.

Causes

Vesicoureteral reflux occurs in two main forms, each with different underlying causes.

Primary vesicoureteral reflux is present at birth and represents the more common type. This condition develops due to a faulty valve mechanism that normally prevents urine from flowing backward.

When this valve doesn’t close properly, urine can travel back up the ureters (the tubes connecting kidneys to bladder).

Many children outgrow primary reflux naturally. As they develop, their ureters grow longer and straighter, which often improves valve function over time. This type frequently runs in families, suggesting a genetic component, though researchers haven’t identified the exact genetic cause.

Secondary vesicoureteral reflux typically results from problems with bladder emptying. Several factors can cause this issue:

• Blockages from tissue folds that prevent complete bladder emptying
• Narrowing of the muscles connecting the bladder to the urethra
• Nerve damage affecting normal bladder emptying function

Unlike the primary form, secondary reflux develops after birth due to these anatomical or functional issues that create pressure in the bladder system, forcing urine backward through the normal one-way valves.

Risk Factors

Several factors can increase the chance of developing vesicoureteral reflux:

• Bladder and Bowel Issues: Children who hold their urine and stool too long might develop this condition. These habits can lead to repeated urinary tract infections, which worsen reflux problems.
• Demographic Factors:
  • White children have higher rates than Black children
  • Girls generally face greater risk than boys (except for cases present at birth, which affect more boys)
  • Children under 2 years old are more vulnerable than older children
• Family Connection: This condition often runs in families. If a parent had vesicoureteral reflux, their children have a higher chance of developing it. Similarly, brothers and sisters of affected children face increased risk.

The combination of these factors can help healthcare providers identify children who might need closer monitoring or earlier screening for this urinary system disorder.

Complications

Kidney damage stands as the primary health concern for those with vesicoureteral reflux. The severity of complications typically corresponds to the reflux intensity.

Potential complications include:

• Kidney Scarring: Untreated urinary tract infections can permanently damage kidney tissue. Extensive scarring might lead to increased blood pressure and kidney failure.

• Blood Pressure Issues: When kidneys sustain damage, they struggle to filter waste properly. This waste buildup can cause elevated blood pressure levels.

• Kidney Function Decline: Scarring can impair a kidney’s filtering ability. This may result in kidney failure, where the organ can no longer perform its essential functions. This serious condition may develop suddenly (acute kidney injury) or gradually over time (chronic kidney disease).