Nothing takes the joy out of sex like a vaginal yeast infection. The most common symptom, present in 90 percent of cases, is intense itching of the vaginal opening and vulva (which is about as sexy as an old shoe). There may also be burning during urination and intercourse, redness and inflammation of vaginal tissues and a curdlike discharge that resembles cottage cheese. Some women say it smells like baking bread.

Unfortunately, this dismal litany of complaints is not at all uncommon. Yeast infections are one ofthe most frequently diagnosed diseases in gynecology, paying an unwelcome visit to three out of every four women at some point during their childbearing years. A quarter ofthese women have multiple, recurrent infections, doctors say.

Usually, the culprit turns out to be a globe-trotting fungus called Candida albicans, in which case the infection is called vulvovaginal candidiasis. Like most fungi, candida thrives in warm, dark, wet places, and the vagina is perfect (although the fungus can also thrive in the throat or in the intestines).