Urinary tract infections (UTIs) typically occur when bacteria from the rectal area enter through the urethra and travel up the urinary tract to the bladder or kidneys.

Typically, UTIs cause urinary symptoms, such as pain or burning during urination. Some mild bladder infections may go away on their own within a couple of days. Most UTIs clear up quickly with antibiotics and home treatment, which includes drinking plenty of water and urinating frequently. The amount of time required to cure the infection and the need for urine tests will vary with the location (bladder or kidneys), frequency, and seriousness of the infection. Kidney infections and UTIs that are complicated by other factors require longer treatment.

Complications of UTIs are not common but do occur. Serious complications can include permanent kidney damage and widespread infection (sepsis), which can be life-threatening. The risk is greater if the infection is not treated or if the infection does not respond to antibiotics.

Some people have many UTIs. They are often new infections (recurrent UTIs), but they can also be the same infection coming back (a relapse). A rapid relapse usually means that treatment failed or there is another problem affecting the urinary tract (not just the infection). But recurrent UTIs in women usually aren't serious.

UTIs in women

UTIs are most common in young to middle-aged women. They occur more often in women than in men because:

• The rectum is closer to the urine outlet (urethra) in women than in men. This allows bacteria present in stool to enter the urinary tract more easily.
• The urethra is shorter in women than in men, which allows bacteria to reach the bladder more easily.
• In women, sexual intercourse can push bacteria into the urethra.
• The fluid produced by a man's prostate gland helps kill bacteria in his urinary tract.

Some women have an ongoing problem with UTIs. If a woman has more than two bladder infections in 6 months or more than three infections in a year, she is said to have recurrent UTIs. Recurrent UTIs usually get better with extended antibiotic treatment. But infection may recur as soon as the woman stops taking antibiotics. For this reason, doctors usually recommend preventive antibiotics.

UTIs in men

Most urinary tract infections in men are caused by bacteria, not by another problem.

But UTIs in older men are more often related to prostate problems. This can make them more difficult to treat. Having an enlarged prostate, which is common in older men, can limit the body's ability to pass urine. Repeated UTIs may indicate prostatitis, epididymitis, or another urinary tract problem.

For more information, see:

• Benign Prostatic Hyperplasia.
• Prostatitis.
• Epididymitis.