Vesicoureteral reflux is the deviant flow of urine from the bladder back to the tubes (ureters) that connect the kidneys to the bladder. Normally, the kidneys filter the blood and extract waste from the blood transforming it to urine. It is usually diagnosed in infants and children. The disorder increases the risk of urinary tract infections, which, if left untreated, can lead to kidney damage.

There are two types of vesicoureteral reflux: primary or secondary. Children with primary vesicoureteral reflux are born with a defect in the valve that normally prevents urine from flowing backward from the bladder into the ureters. Secondary vesicoureteral reflux is due to a urinary tract malfunction, often caused by infection.

Treatment, which includes medication or surgery, aims at preventing kidney damage.


The symptoms can include:

  • A burning sensation when urinating
  • A strong, persistent urge to urinate
  • Passing frequent, small amounts of urine
  • Blood in the urine or cloudy, strong-smelling urine
  • Fever
  • Pain in the side (flank) or abdomen
  • Hesitancy to urinate or holding urine to avoid the burning sensation

As the child gets older, untreated vesicoureteral reflux can lead to other signs and symptoms, including:

  • Bed-wetting
  • Constipation or loss of control over bowel movements
  • High blood pressure
  • Protein in urine
  • Kidney failure

In addition, the child may change his/her appetite and mood, have diarrhea and vomit.


Kidneys, ureters, bladder and urethra are parts of the urinary system which plays a role in removing waste products from the body. The kidneys filter waste, water and electrolytes minerals that help maintain the balance of fluids in the blood and body.

Ureters are tubes that carry urine from the kidneys down to the bladder, where it is stored until it exits the body through another tube (the urethra) during urination.

Vesicoureteral reflux can develop in two forms, primary and secondary:

In the primary vesicoureteral reflux the cause of this more common form is a defect which is congenital. This type of vesicoureteral reflux tends to run in families, which indicates that it may be genetic, but the exact cause of the defect is unknown.

In secondary vesicoureteral reflux the cause is a blockage or malfunction in the urinary system most commonly results from recurrent UTIs, which may cause swelling of a the ureter.

Risk Factors

Risk factors for vesicoureteral reflux include: race, sex, age and family history.


Kidney damage is the primary concern with vesicoureteral reflux. The complications are more serious if the reflux is severe. They may include:

  • Kidney (renal) scarring.
  • High blood pressure (hypertension).
  • Kidney failure.


Being a congenital defect, primary vesicoureteral reflux cannot be prevented. Regarding secondary vesicoureteral reflux, which is due to a urinary tract malfunction, often caused by infection, the disease is prevented by early treatment or preventing infection.