Female gender is one of the main risk factors for bladder infection. Because of the short urethral length, bacteria can gain access to the bladder much easier than in males.
Pregnancy also increases susceptibility to bladder infection. In fact, some pregnant women may have some type of urinary infections, including bladder infection, during their pregnancy. Pressure applied to the urinary structures by an enlarging uterus of pregnancy can disrupt the natural flow of urine triggering a bladder infection.
In postmenopausal women, physiological factors (vaginal dryness, urinary incontinence, urinary retention, and prolapse of the pelvic organs) can potentially increase the chances of developing bladder infections. Sexual intercourse in women is another risk factor for bladder infection.
In men with prostate enlargement, bladder infection is also more common than in general male population. Prostate enlargement can lead to obstruction of the normal flow of urine out of the bladder and into the urethra. Residual urine can then become infected.
Elderly persons are also at higher risk of suffering bladder infection as are individuals who take medications that weaken the immune defense system.
Urinary catheters (Foley catheters) are another potential risk for bladder infection. These urinary catheters are typically used in settings where an individual may not be able to urinate naturally. Urinary catheters simply provide a physical vehicle to transport bacteria from outside directly into the bladder and the urinary system. Foley catheters are commonly used in patients with:
- Severe illness
- Limited mobility
- Urinary incontinence (inability to hold their urine)
- Bladder obstruction and urinary retention (prostate enlargement, urethral scarring, prostate cancer)
- Bladder trauma
- Bladder cancer
- Bladder dysfunction due to neurologic conditions
- Inability to get out of bed
Bladder infection is more commonly seen in patients with paralytic conditions, such as multiple sclerosis (MS), stroke, and other diseases of the nervous system, than in the general public. In these and other similar neurologic diseases, bladder function may be impaired due to abnormal nervous system control of the bladder (neurogenic bladder). As a result, urine may be retained in the bladder and not completely emptied after voiding. Urinary retention can be a cause of bladder infection. Furthermore, if urinary retention becomes more serious causing pain and kidney dysfunction, Foley catheters may become necessary to empty the bladder and relieve the bladder pressure caused by excessive retention of urine. A catheter, in turn, can substantially increase the risk of bladder infection.
In addition to the Foley catheter, any instrumentation of the urinary tract or nearby structures can potentially lead to cystitis. Medical procedures (cystoscopy, bladder biopsy, prostate procedures), vaginal pessary, and IUD (intrauterine device) placement for birth control can pose an increased risk of developing bladder infection.