Urinary Tract Infection (UTI)

A urinary tract infection (UTI) is an infection in any part of your urinary system. That can include your kidneys, ureters, bladder and/or your urethra. Most infections involve the lower urinary tract — the bladder and the urethra.

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.

• 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.

Other risk factors for UTIs include:

• Urinary tract abnormalities. Babies born with urinary tract abnormalities that don’t allow urine to leave the body normally or cause urine to back up in the urethra have an increased risk of UTIs.
• Blockages in the urinary tract. Kidney stones or an enlarged prostate can trap urine in the bladder and increase the risk of UTIs.
• A suppressed immune system. Diabetes and other diseases that impair the immune system — the body’s defense against germs — can increase the risk of UTIs.
• Catheter use. People who can’t urinate on their own and use a tube (catheter) to urinate have an increased risk of UTIs. This may include people who are hospitalized, people with neurological problems that make it difficult to control their ability to urinate and people who are paralyzed.
• A recent urinary procedure. Urinary surgery or an exam of your urinary tract that involves medical instruments can both increase your risk of developing a urinary tract infection.