What causes bladder infections?

Kevin W. Windom, MD
OBGYN (Obstetrics & Gynecology)
Bladder infections are caused by bacteria that occur in fecal material.  The most common bacteria seen in a urinary tract infection is E. coli, and this is also commonly seen in stool.  Urinary tract infections can be caused by sexual intercourse, waiting too long to urinate, inadequate bladder emptying, and some forms of birth control such as spermicidal jelly and the use of diaphragms.  There are medical problems that can increase the risk of urinary tract infections, and the most common is diabetes.  Some diabetics are not able to completely empty their bladder and chronically have high residual volumes of urine in their bladder.  Lastly, women who go through menopause have a lack of estrogen in the vaginal tissue and can have an increased risk of bladder infections.  The reason is that there are numerous estrogen receptors in the vagina, and a lack of estrogen can cause the vaginal tissue to become atrophic (or dry).  In this situation, it is very easy for the bacteria to flourish in the vagina then travel from the vagina to the urethra, causing a bladder infection.   One way to decrease occurrences of urinary tract infections is to wipe from front to back and eliminate urine after intercourse.
Jacob Teitelbaum
Integrative Medicine

Bladder infections, also called "cystitis," are very common in females because the opening from the outside of the body to inside the bladder is very short. This makes it easier for bacteria (usually the healthy E. coli which come from our rectum/stool) to get into the bladder. While most bacterial infections simply get washed out each time you urinate, the E. coli have little "Velcro-like sticky pads" on them that allow them to stick to the bladder wall - so they don"t wash out.

Although bladder infections can occur without symptoms, more often they trigger an intense urge to urinate (urgency), urinating frequently (even when there is little urine), and burning on urination (called "dysuria"). Blood visible in the urine is less common, and warrants a trip to the doctor.

Before beginning antibiotics, it is good to have the doctor get a urine sample to do a culture to test for bacteria. Often in women with recurrent bladder symptoms there is no infection, and the antibiotics simply make the problem worse in the long run.

In men, because the penis makes it a long trip for bacteria, bladder infections are uncommon unless there is a blockage. This usually occurs from prostate problems in men over 60 or from kidney stones in younger men. In a young man with urinary burning, prostatitis is more likely than a bladder infection. If you wake with even a drop of discharge (before you urinate) on the tip of your penis, you also need to check for sexually transmitted infections (it may not be, but have it checked).

Bladder infections are much more common in women. Also referred to as cystitis or inflammation of the bladder, these infections are caused by bacteria that make their way into the urethra.

Women have a shorter urethra, the tube that carries urine out of the bladder. The shorter passageway makes it easier for bacteria from other parts of the body to invade the urinary tract.

Bladder infections are not serious if treated right away. But they tend to come back in some people. They rarely lead to kidney infections, which is much more serious.

In men, a bladder infection may be a symptom of an underlying disorder and is generally a cause for concern.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.