The kidney is usually sterile, meaning that no bacteria are normally present within it. In VUR, bacteria that enter through the urinary tract may be carried back up the ureter with the urine. These bacteria can enter the kidney, causing severe infection. Most cases of VUR are due to a defect in the way the ureter is implanted into the bladder. VUR alone does not usually cause symptoms.
Symptoms develop when an infection has set in.
The usual symptoms of infection include frequent need to urinate, pain or burning with urination, and blood or pus in the urine. Occasionally, VUR is suspected when a child has a difficult time becoming toilet trained. In these cases, the bladder may become irritable and spasm, because it is never totally empty of urine. When the kidneys have been damaged, high blood pressure may develop. Diagnosis VUR is diagnosed by taking a series of x-ray pictures.