Urinary tract infections are among the most common infections in children. One of the three infections that should be considered and controlled in a child with fever is urinary tract infection (the other two are respiratory tract and middle ear infections). If urinary tract infection also affects the kidney, it causes permanent tissue destruction in the kidney and impairs its functions. Recurrent infections can cause complete loss of kidneys. Vesicoureteral reflux is the first among the causes of recurrent urinary tract infections in children. Normally, it is not possible for the urine from the bladder to return to the urinary canals and kidneys. However, if the mechanism that prevents this reflux is broken, the urine escapes back, making it easier for the infection in the bladder to settle in the kidneys. The urine that escapes during urination cannot be excreted and accumulates in the kidneys, can cause damage by increasing the pressure. Also, bacteria gain the chance to stay in the excretory system for a longer time and cause disease by multiplying. Vesicoureteral reflux may be of varying degrees. Mild types can be expected to pass under control for a while. Severe types or those with infection that do not go away on their own are treated surgically.