In a urinary tract infection (UTI), bacteria usually enter the urinary tract through the urethra. They may then travel up the urinary tract and infect the bladder (cystitis) and the kidneys (pyelonephritis). Most UTIs in children clear up quickly with proper antibiotic treatment.

The biggest concern over UTIs in children is that they can cause permanent kidney damage and scarring. Repeated scarring can lead to high blood pressure and reduced kidney function, including kidney failure. Infants and young children seem to be at higher risk for this complication.

The risk of irreversible kidney damage makes early medical evaluation and treatment of UTIs in infants and young children very important. Unfortunately, detecting UTIs in infants and young children can be difficult. Unlike symptoms in older children and adults, symptoms in the very young can be vague and inconsistent.

Serious short-term complications of UTIs are unusual but do occur. They include an abscess in the urinary tract, acute kidney failure, and widespread infection (sepsis), which can be life-threatening. These complications are more likely in premature infants and newborns and in infants with urinary tract obstructions.

Recurrent UTIs

Infants and young children often develop another UTI during the months after their first UTI. If an infection comes back (recurs), it usually happens within the same year as the first UTI.

Recurrent UTIs in a child can mean that there is a problem with the structure or function of the urinary tract. Because repeated infections increase the risk of permanent kidney damage, your child's doctor will evaluate and monitor any structural or functional problems. In some cases, your child may need surgical correction.