Approximately 95 percent of urinary tract infections, or UTIs, are caused by bacteria moving up the urethra and entering the bladder, notes the Merck Manuals. A bladder infection is one of several types of UTI, and the University of Maryland Medical Center notes that more than half of all women will experience a minimum of one UTI at some point during their lives. Bladder infections--also referred to as cystitis--are particularly common among women of child-bearing age.
Escherichia Coli
Escherichia coli, or E. coli, are a group of bacteria that normally live in the human colon. When those bacteria spread from the area of the anus and enter the urethra they can cause infection of the urethra. If they travel from the urethra to the bladder, they can cause a bladder infection. E. coli causes approximately 80 percent of all UTIs, notes the Penn State Milton S. Hershey Medical Center.
Group B Streptococcus and Other Bacteria
Approximately 25 percent of American women of all races carry the Group B streptococcus--or GBS--bacteria, notes the Centers for Disease Control and Prevention. This bacteria often lives in the rectum and vagina without affecting a woman's health or causing any symptoms. It can, however, cause bladder infections, and the CDC warns that any pregnant woman with a GBS bladder infection should receive antibiotics before the birth of her child to prevent infection of the baby during birth.
The Penn State Milton S. Hershey Medical Center lists the Enterobacter, Proteus, Staphylococcus saprophyticus and Klebsiella bacteria as other species of bacteria that can cause bladder infections.
Sexual Intercourse
Many women develop bladder infections after having sexual intercourse. Bladder infections are not sexually-transmitted diseases, but the rubbing action during intercourse may move bacteria towards the urethra and may massage the bacteria into the urethral opening.
Retention of Urine
Holding in urine when the urge to urinate arises may increase the risk of developing a bladder infection. The National Institute of Diabetes and Digestive and Kidney Diseases explains that urine is normally sterile, and it washes away any bacteria in the urinary tract. Retention of the urine may facilitate the growth of those bacteria. The act of retaining the urine can also result in muscle tightness that may cause partial retention of urine in the bladder when the person does eventually urinate.
References
- Merck Manual for Healthcare Professionals: Bacterial Urinary Tract Infections
- University of Maryland Medical Center: Urinary Tract Infection in Women
- Merck Manual of Health and Ageing: Urinary Tract Infections
- The Centers for Disease Control and Prevention: Group B Strep Prevention
- Penn State Milton S. Hershey Medical Center: Bladder Infection
