Cystitis - Causes

The causes of cystitis are somewhat different in women than in men. Most bladder infections in women are so-called ascending (going upward) infections. Ascending infections are caused when disease agents travel upward through the urethra from outside the body. The female urethra is relatively short, about 1 to 2 inches in length. Microorganisms that cause disease can travel this distance very easily. The organism that most commonly causes cystitis in women is Escherichia coli (or E. coli ; pronounced ESH-ur-ickee-uh KO-lie). It is responsible for about 80 percent of all cases of the disease.

Other organisms that can cause cystitis include Staphylococcus saprophyticus (pronounced STAFF-uh-lo-kock-us SAP-ro-FIT-ick-us), and members of the Klebsiella (pronounced KLEB-see-ell-uh), Enterobacter (pronounced EN-terr-o-BACK-tur), and Proteus (pronounced PRO-tee-us) families of bacteria.

A number of other factors increase a woman's risk for cystitis. These factors include:

• Sexual intercourse. The more sexual partners a woman has, the greater her risk for cystitis.
• Use of a diaphragm for birth control
• An unusually short urethra
• Diabetes (see diabetes entry)
• Poor personal hygiene. Bacteria from vaginal discharges or feces can easily enter the female urethra. The opening to the urethra in women is very close to the vagina and the anus.
• History of previous UTIs. About 80 percent of women who have one case of cystitis will develop another case within two years.

Males

Cystitis in men usually occurs as a complication of kidney or prostate gland infection. The most common cause of cystitis in men, as in women, is the bacterium Escherichia coli. Factors that increase men's risk for cystitis include:

• Lack of circumcision. Circumcision is the procedure in which the foreskin is removed from a man's penis. If the foreskin has not been removed, bacteria can grow beneath it. The bacteria can then travel up the urethra to the bladder.
• Urinary catheterization. Urinary catheterization is a medical procedure in which a long, thin tube (a catheter) is inserted into the urethra. It is pushed up into the bladder. Some men require this procedure if they are unable to urinate normally. The presence of the catheter provides a pathway by which bacteria can travel up into the bladder and cause infection.