A urinary
tract infection (UTI) is an infection most often caused
by bacteria that affects any part of the urinary system,
including the bladder, urethra, uterus, or kidneys. UTIs
are classified as upper UTIs (Kidney infections) or lower
UTIs (bladder infections). They are the most frequent bacterial
infection in women and occur most frequently between the
ages of 16 and 35 years.