Urine itself is normally sterile, that is, it contains no bacteria, viruses or fungi. Infection causing bacteria usually enters the urinary system by way of the opening of the urethra. The urinary system is designed to ward off infection, but they do sometimes occur.
Most UTIs are caused by the Escherichia coli (E. coli) bacteria, which normally lives in the colon. Other infection causing microorganisms are Chlamydia and Mycoplasma, but they tend to remain limited to the urethra and reproductive system. Unlike E. coli, Chlamydia and Mycoplasma may be sexually transmitted, and infections require treatment of both partners.
For unknown reasons, some people seem more prone to UTIs than others. However, some standard risk factors are:
- Gender: Women are much more likely to get a UTI than men, possibly because they have a shorter urethra, which shortens the distance bacteria must travel to reach the bladder.
- Sexual intercourse: Sexual intercourse can result in bacteria being pushed into the urethra.
- Pregnancy: Studies suggest that the hormonal changes during pregnancy may be a risk factor.
- Menopause: The loss of estrogen makes the tissues of the vagina, urethra and the base of the bladder thinner and more fragile and therefore possibly more prone to infection.
- Any obstruction that stops or slows the normal flow of urine, including:
- Elarged prostate .
- Kdney stone.
- Anormalities in the urinary tract, including:
- Diverticula, small “pouches” in the bladder and urethra that can hold bacteria.
- Blockages (such as an enlarged bladder) that stop the bladder from emptying completely.
- Diabetes : Diabetes leads to sugar in the urine which appears to be a risk factor.
- Weak immune system: A variety of conditions (such as HIV) or treatments (such as chemotherapy) can suppress the immune system, making it harder for the body to fight off infection.
- Bladder catheters: Prolonged use of bladder catheters can increase risk.
- Blood type: NIH funded research is studying the connection between a woman's blood type and her risk of getting a UTI.
Some forms of birth control:
Some studies suggest diaphragm use may be a risk factor;
Others suggest condoms used with spermicidal foam may be a risk factor;
None of this research is conclusive. |
