When you think of yeast, you might imagine the microorganisms that make bread dough rise (there are more than 200 billion in a packet of dry yeast).

But there are other forms of yeast that live in the human body, helping your digestive and immune systems function and assisting in the absorption of vitamins and minerals from food. Sometimes they get thrown out of balance. When that happens in the vagina, a yeast called Candida causes a condition known as vaginal candidiasis.

This infection is common — an estimated 1.4 million outpatient visits for vaginal candidiasis happen annually in the U.S.

Sometimes because of medications (oral and inhaled corticosteroids and immunosuppressive drugs), chronic health conditions (diabetes, for example), or lifestyle habits (wearing sweaty, tight gym clothes, douching), the infections become chronic, occurring three or more times a year. That is called recurrent vulvovaginal candidiasis (RVVC).

Nearly 75% of adult women experience one yeast infection in their lifetime; approximately half experience a recurrence; and up to 9% of those women develop RVVC.

Until now, there's been no medication specifically targeting chronic candidiasis. But recently the Food and Drug Administration approved the first-ever drug  that treats RVVC, called oteseconazole.

In two studies, 93.3% and 96.1% of women with RVVC who received the treatment didn't experience a recurrence during a 48-week maintenance period.

But — and there's always a but — it's only for postmenopausal women or those who are permanently infertile, because it is embryo-fetal toxic.

However, if you suffer with RVVC and meet those criteria, talk to your doctor about the benefits and risks of this long-awaited treatment.