Bladder Home > Why Do Urinary Tract Infections Occur in Children?
Although normal urine contains no bacteria (germs), bacteria can get into the urinary tract and the urine from the skin around the rectum and genitals. This can occur when the bacteria travel up the urethra into the bladder. When this happens, the bacteria can infect and inflame the bladder and cause swelling and pain in the lower abdomen (stomach) and side. This bladder infection is called cystitis.
If the bacteria travel up through the ureters to the kidneys, a kidney infection can develop, which is usually accompanied by pain and fever. Kidney infections are much more serious than bladder infections.
In some children, a urinary tract infection may be a sign of an abnormal urinary tract that may be prone to repeated problems. For this reason, when a child has a urinary infection, doctors often recommend additional tests. Some children develop UTIs because they are prone to them, just as other children are prone to getting coughs, colds, or ear infections. Or a child may happen to be infected by a type of bacteria with a special ability to cause urinary tract infections.
Children who frequently delay a trip to the bathroom are more likely to develop urinary tract infections. Regular urination helps keep the tract sterile by flushing away bacteria; holding in urine allows bacteria to grow. Keeping the sphincter muscle tight for a long time also makes it more difficult to relax that muscle when it is time to urinate. As a result, the child's bladder may not empty completely, which can set the stage for a UTI.
(Click Causes of Childhood Urinary Tract Infections for more information.)