The urinary tract includes the kidneys, bladder, ureters, and urethra. Urinary tract infections (UTIs) are far more common in women than men. Urinary tract infections have different names depending on which part of the urinary tract is infected.
Among newborns, UTIs are more common in boys, but by one year of age, they are ten times more likely to occur in girls. The rate of infection is higher for sexually active women - between 16 and 35 years old - than for men. As many as 50% to 60% of North American women have had at least one UTI in their lifetime. Among seniors, the gender difference in infection rates diminishes, however, rates of infection in seniors living at home or in care facilities or hospitals remains high.
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) that'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 UTIs 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. Women who are pregnant or have diabetes have been reported to have higher rates of UTIs when compared to women who are not pregnant and do not have diabetes.
In addition to bladder infections, men may get infections of the prostate (prostatitis). In fact, bacteria from the prostate can lead to recurrent UTIs 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 seniors, UTIs are often due to problems with incomplete 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), certain medications, 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.
Common UTI symptoms may include:
Bladder infections (cystitis) often result in urine that's dark and cloudy. In addition to the above symptoms, bacterial prostatitis (infection of a man's prostate gland) can also cause fever, chills, low back pain, and discomfort or pain around the anus or perineal region. In some cases, a kidney infection (pyelonephritis) can follow a bladder infection by a couple of days, causing abdominal pain, flank pain, nausea, vomiting, fever, and chills.
In infants or children, UTIs can cause symptoms such as vomiting or fever and prevent normal weight gain.
Seniors don't necessarily have symptoms that are common to UTIs. Instead, they often have gastrointestinal symptoms including changes in eating habits, or mental signs like confusion. People with catheters or neurologic disorders might only complain of side pains and a fever.
Sometimes, there are large amounts of bacteria in the urine but no obvious symptoms of UTIs. This is known as asymptomatic bacteriuria and it's common in seniors. Pregnant women and kidney transplant patients may also develop this type of infection.
Symptomatic abacteriuria is the opposite: people have UTI symptoms, but bacteria levels in the urine are low. Even with very little bacteria present, a UTI can still be diagnosed.