When you have a urinary tract infection, the lining of the bladder and urethra becomes irritated just as the inside of your nose or throat does when you have a cold. The irritation can cause pain in your abdomen and pelvic area and may make you feel the need to constantly empty your bladder. In addition, you may feel a burning sensation as the urine comes out. You may notice that the urine has an unpleasant odor or a cloudy look. At times, bladder infections may also cause low back pain, fever, or chills.
Kidney infections produce fever and back pain much more commonly than do bladder infections.
If a kidney infection is not treated promptly, the bacteria may spread to the bloodstream and cause a life-threatening infection. In an infant or young child, the signs of a urinary tract infection may not be clear, especially if the child is too young to tell you just how he or she feels. Instead, the child may be irritable, not eat as much as usual, have a fever or loose bowel movements, or just not seem healthy. If the symptoms last more than a day, they may signal the need to see a doctor. Only by consulting a doctor can you find out for certain whether you or your child has a urinary tract infection.