Bladder infections are known as cystitis or inflammation of the bladder. They are common in women, but very rare in men. More than half of all women get at least one bladder infection at some time in their lives. However, a man's chance of getting cystitis increases as he ages, due to in part to an increase in prostate size.
Doctors aren't sure exactly why women have many more bladder infections than men. They suspect it may be because women have a shorter urethra, the tube that carries urine out of the bladder. This relatively short passageway -- only about an inch and a half long -- makes it easier for bacteria to find their way into the bladder. Also, the opening to a woman's urethra lies close to both the vagina and the anus. That makes it easier for bacteria from those areas to get into the urinary tract.
Bladder infections are not serious if treated right away. But they tend to come back in some people. Rarely, this can lead to kidney infections, which are more serious and may result in permanent kidney damage. So it's very important to treat the underlying causes of a bladder infection and to take preventive steps to keep them from coming back.
In elderly people, bladder infections are often difficult to diagnose. The symptoms are less specific and are frequently blamed on aging. Older people who suddenly become incontinent or who begin acting lethargic or confused should be checked by a doctor for a bladder infection.
What Causes Bladder Infections?
Most bladder infections are caused by various strains of E. coli, bacteria that normally live in the gut.
Women sometimes get bladder infections after sex. Vaginal intercourse makes it easier for bacteria to reach the bladder through the urethra. The risk for bladder infection -- dubbed "honeymoon cystitis" -- increases with frequent sex. Pregnant women, whose urinary tracts change in response to hormones and increased kidney function, are also prone to infections. Diaphragms and the use of spermicides alone or with condoms also increase the risk of urinary tract infections.