All About Urinary Tract Infections (UTIs)

Urinary tract infections (UTIs) are the second most common infection among women, behind colds and flu. And for many women, they're as painful as they are prevalent. For some women, it's worse than having a cavity filled, says Kristine E. Whitmore, MD, clinical associate professor of urology at Medical College of Pennsylvania-Hahnemann in Philadelphia. Unfortunately, the pain isn't the worst part -- if you're pregnant, UTIs are potentially dangerous to you and your baby. Here's the scoop on what causes them, what they feel like, and how to prevent them.

If you've ever had a UTI, you're all too familiar with the symptoms. You need to go to the bathroom every 30 minutes to an hour. Often nothing comes out. And when you do go, it hurts or burns. You may even have back pain or bloody urine.

So what causes all of this? Ninety percent of the time, it's Escherichia coli (E. coli), a bacterium found around the anal area, that becomes trapped in the bladder. One of the easiest routes is via toilet paper; if you wipe back to front, the germ can make its way up your urethra, the tube that connects the bladder to the outside world. Female biology makes it even easier -- women have a short urethra (it's 4 centimeters long, while the average man's is 12) -- so it takes the bacteria little time to get to the bladder.

There are a number of other ways to get infected. Not drinking enough fluids results in infrequent urination, and urinating is an effective way of clearing germs from the bladder and urethra. And diabetics or people with urinary tract abnormalities are more at risk. But chances are, if you've had a UTI, you got it from sex. Bacteria from the colon and vagina can get into the urethra during foreplay and intercourse, Dr. Whitmore says. Vigorous sex can cause the bladder to become inflamed, so bacteria stick to its lining. The end result of all that sex -- pregnancy and childbirth -- can leave you more susceptible to UTIs, too. The enlarged uterus and increase in the hormone progesterone prevent the bladder from emptying completely, explains Kevin Ault, MD, assistant professor of obstetrics and gynecology at the University of Iowa. As a result, there's a pool of urine left in the bladder, in which bacteria can flourish. And the more time you spend pushing the baby out, the longer the baby's head presses against the bladder, brushing it and making it hospitable to bacteria.