Causes
Women are more likely to get UTIs than men. That's because women have
a shorter urethra - the tube that carries urine out of the bladder - and it's
closer to the rectum. This allows bacteria easier access to a woman's urinary
tract. After urinating, wiping from the back to the front pushes bacteria from
the rectal area towards the urethra, which can lead to a UTI. Sexual intercourse
increases the risk for UTI because bacteria are spread upward into the bladder.Using
diaphragms and spermicides can also increase the risk for UTIs because the normal
bacteria around the urethra may be changed, making infection more likely. Pregnancy
also makes some women more susceptible to UTIs.
In addition to bladder infections, men may get infections of the prostate
(prostatitis). In fact, bacteria from the prostate can lead to recurrent
urinary tract infections in men. For infants and children, UTIs can be associated
with particularly narrow urinary tracts, or with a condition where the urine
is pushed back up into the kidneys.
In elderly people, UTIs are often due to problems with bladder emptying
or bowel incontinence. The urine that's left behind contains bacteria that
can easily spread to the bladder. Conditions that prevent complete emptying
of the bladder include urinary tract blockages, kidney stones, neurologic diseases
(such as stroke or spinal cord injury), and having an inserted catheter, as
in the case of hospitalized patients.
On very rare occasions, UTIs can be caused by bacteria that have spread from
infections elsewhere in the body.