In the middle of a grueling economics midterm, you get the "urge" again. You've already urinated about 20 times this morning, and can barely concentrate due to the burning sensation "down under." The guy sitting beside you glares at you and clears his throat every time you squirm uncomfortably in your seat.

You wonder, "Is this a bladder infection?" and "How did I get it?"

It's not like you've been wading in contaminated waters like the Survivor contestants.

"Time's up," the professor calls out, and you hand in your unfinished test, thankful that you can finally run to the bathroom (again).

This is not an uncommon scenario for many women on campus.

Urinary tract infections (UTIs) are common, with as many as 50 percent of women having at least one in their lifetime.

Causes

UTIs occur more frequently in women than men due to anatomical differences.

Women have short urethras (only one-and-a-half inches long) and the opening is close to both the rectum and vagina, making it easier to introduce bacteria during wiping or intercourse. E. coli, a bacteria that normally lives in our digestive system, causes the majority of UTIs.

UTIs can be lower, affecting the bladder and urethra or upper (pyelonephritis), involving the kidneys and ureters.

In some women, using a spermicide with a condom or diaphragm can increase the risk of UTIs.

Spermicide may change the normal vaginal flora/environment, allowing more harmful bacteria to colonize the vagina and urethra.

If you use spermicide and have had a UTI, you may want to talk with your health care provider to determine the best way to protect against sexually transmitted diseases and pregnancy that won't increase your risk for UTIs.

Symptoms

Symptoms of a lower UTI include burning with urination, urgency, urinating small amounts, lower abdominal pressure and/or blood in the urine.

In addition to these symptoms, upper UTIs may also cause fever, chills, nausea, vomiting and pain in the back or side.

Treatment

UTIs are diagnosed by taking a history, performing a physical exam and testing the urine. If the symptoms and/or urinalysis indicate an infection is present, antibiotics are prescribed.

To prevent a recurrent infection, all of the antibiotic doses should be finished. Because some UTI symptoms can overlap with those seen in certain sexually transmitted infections, your clinician may recommend additional testing. Drinking plenty of water during treatment is essential to help flush the organism from the bladder.

Cranberry juice may be helpful by making the bladder walls "slippery" so that bacteria cannot attach.

To determine if you are drinking enough to help treat a bladder infection, your urine should be clear by noon (i.e. not yellow) and stay clear the remainder of the day. Water and cranberry juice are the best choices.

Limit the amount of other fruit juices and milk you consume, as these can alkalinize the urine and make the antibiotic less effective.

You should also stay away from alcohol and caffeine because these can dehydrate your system.

Upper UTIs are more serious due to the risk of kidney scarring and require closer follow-up, longer antibiotic courses and hospitalization in some cases.

Prevention

To prevent UTIs, always urinate after intercourse, wipe front-to-back after urination or a bowel movement, empty the bladder completely and often and maintain good hygiene.

Avoiding the contaminated waters of "The Amazon" can't hurt, either.

For more information about UTIs, see the UHS Web site at www.sa.psu.edu/uhs/uti.htm.