If you are prone to recurrent UTIs, you can head them off before they take hold.

Unless you're in the fortunate minority of women who have never had a urinary tract infection (UTI), you know the symptoms well. You might feel a frequent urgency to urinate yet pass little urine when you go. Your urine might be cloudy, blood-tinged, and strong-smelling. For 25% to 30% of women who've had a  urinary tract infection, the infection returns within six months.

If you have repeated UTIs, you've experienced the toll they take on your life. However, you may take some comfort in knowing that they aren't likely to be the result of anything you've done. "Recurrent UTIs aren't due to poor hygiene or something else that women have brought on themselves. Some women are just prone to UTIs," says infectious diseases specialist Dr. Kalpana Gupta, a lecturer in medicine at Harvard Medical School.

The infections are usually caused by Escherichia coli, a bacterium that lives in the intestinal system. If E. coli are carried from the rectum to the vagina, they can enter the urethra (the tube that carries urine from the bladder) and infect the bladder.

Risk factors for UTI vary with age. Before menopause, the most common risk factors are sexual intercourse and use of spermicides. It's thought that sex increases the number of bacteria in the bladder, and many experts advise women to urinate after sex to flush them out. Spermicides may kill off Lactobacilli, beneficial bacteria in the vagina, making it easier for E. coli to move in.

After menopause, certain physical changes help set the stage for UTIs. The numbers of Lactobacilli in the vagina naturally decline. The bladder also contracts less strongly than it once did, making it more difficult to empty it completely.

In both premenopausal and postmenopausal women, genes play a role as well. Having a mother or sister who has frequent UTIs is also a risk factor.

These approaches have some evidence to support them:

Drink plenty of fluids every day. Aim for about 2 to 3 liters.

Use alternative contraception that does not include a spermicide.

Empty your bladder immediately following sexual intercourse.

Consider vaginal estrogen therapy for post-menopausal women.

Wipe front to back, although this has not been scientifically proven to make a difference.

Taking a low dose of one of the antibiotics used to treat UTI is the most common way of dealing with recurrences. However, bacteria may become resistant to an antibiotic overtime and it may not be effective in treating subsequent infections. "This is an area in which women can experiment and find which solution works for them," Dr. Gupta says. There are several options if you have a prescription on hand:

taking a low dose daily for six months or longer

using only after you have sex

waiting until you have UTI symptoms.

If you have recurrent UTIs, talk to your clinician. The two of you can come up with a plan that is likely to be effective for you.

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