Female anatomy. A woman has a shorter urethra than a man does, which shortens the distance that bacteria must travel to reach the bladder.
Sexual activity. Sexually active women tend to have more UTIs than do women who aren't sexually active. Having a new sexual partner also increases your risk.
Certain types of birth control. Women who use diaphragms for birth control may be at higher risk, as well as women who use spermicidal agents.
Menopause. After menopause, a decline in circulating estrogen causes changes in the urinary tract that make you more vulnerable to infection.”