This Is What Causes Yeast Infections—Plus, How You Can Prevent Them


If you've had a yeast infection before, you're probably already familiar with the telltale symptoms—intense itch, irritation, and a thick, white discharge. The uncomfortable down-there condition is triggered by an overgrowth of Candida yeast, most commonly Candida albicans. Candida lives normally in the intestinal tract, but a change in the balance of yeast and bacteria can cause a yeast infection to develop.

Women of all ages—from adolescents to menopausal women—can develop yeast infections, but some are more prone than others, says Alyssa Dweck, MD, a gynecologist and assistant clinical professor at Mount Sinai School of Medicine based in Westchester County, NY. Pregnancy, diabetes, antibiotic use, or having any sort of immunosuppression (due to HIV or chronic steroid use, for example) may increase your risk. Additionally, high estrogen levels may drive Candida overgrowth, making some women on the pill more susceptible as well.

Experts are conflicted on whether or not certain lifestyle factors can contribute to yeast overgrowth. "There are lots of questions about clothing choices and yeast infections, but I think the jury is still out on this," says Dr. Dweck. "For women who are very prone to yeast infections, the type of material they’re wearing—be it underwear, workout clothes, yoga pants—may matter, since synthetic or non-breathable fabric could increase their chance of infection."

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That said, there’s no need to replace your entire underwear drawer just yet. "Many women can wear anything and be totally fine," says Dr. Dweck. "It’s really for those who are particularly prone to yeast that might find it helpful to modify their habits."

That includes sleeping in underwear made of a breathable fabric (like cotton), not douching, and avoiding sanitary pads or tampons that are scented. Sex could play a role, as well, although Dr. Dweck notes that more research is needed.

The bottom line? "A simple, one-time yeast infection is no big deal," says Dr. Dweck. But if you seem to be getting them often, it's important to visit your doctor and make sure there isn't an underlying cause. "Your doctor can check for other problems that might be leading you to get constant infections."