A vaginal yeast infection is a fungal infection that causes irritation, discharge and intense itchiness of the vagina and the vulva — the tissues at the vaginal opening.
Also called vaginal candidiasis, vaginal yeast infection affects up to 3 out of 4 women at some point in their lifetimes. Many women experience at least two episodes.
A vaginal yeast infection isn’t considered a sexually transmitted infection. But, there’s an increased risk of vaginal yeast infection at the time of first regular sexual activity. There’s also some evidence that infections may be linked to mouth to genital contact (oral-genital sex).
Medications can effectively treat vaginal yeast infections. If you have recurrent yeast infections — four or more within a year — you may need a longer treatment course and a maintenance plan.
Yeast infection symptoms can range from mild to moderate, and include:
You might have a complicated yeast infection if:
The fungus candida albicans is responsible for most vaginal yeast infections.
Your vagina naturally contains a balanced mix of yeast, including candida, and bacteria. Certain bacteria (lactobacillus) act to prevent an overgrowth of yeast.
But that balance can be disrupted. An overgrowth of candida or penetration of the fungus into deeper vaginal cell layers causes the signs and symptoms of a yeast infection.
Overgrowth of yeast can result from:
Candida albicans is the most common type of fungus to cause yeast infections. Yeast infections caused by other types of candida fungus can be more difficult to treat, and generally need more-aggressive therapies.