Your urinary tract is the system that makes urine and carries it out of your body. It includes your bladder and kidneys and the tubes that connect them. When germs get into this system, they can cause an infection.
Most urinary tract infections (UTIs) are bladder infections. A bladder infection usually is not serious if it is treated right away. If you do not take care of a bladder infection, it can spread to your kidneys. A kidney infection is serious and can cause permanent damage.