There are many different causes of urinary tract infection and they happen in both men and women. In general however, they are more common in women and many women experience more than one infection during their lifetimes. Most infections result from the bacteria around the urethra ascending into the bladder.
- Infection of the bladder (cystitis). This type of UTI is usually caused by Escherichia coli (E. coli), a type of bacteria commonly found in the gastrointestinal (GI) tract. However, sometimes other bacteria are responsible. Sexual intercourse may lead to cystitis, but you don’t have to be sexually active to develop it. All women are at risk of cystitis because of their anatomy — specifically, the short distance from the urethra to the anus and the urethral opening to the bladder.
- Infection of the urethra (urethritis). This type of UTI can occur when GI bacteria spread from the anus to the urethra. Also, because the female urethra is close to the vagina, sexually transmitted infections, such as herpes, gonorrhea, chlamydia and mycoplasma, can cause urethritis.
Infections limited to your bladder can be painful and annoying. However, serious consequences can occur if a UTI spreads to your kidneys, so it is important to diagnose and treat a urinary tract infection correctly. Infections can also be the result of stones, foreign bodies, hormonal changes, and poor bladder emptying.