Overview
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.
Symptoms
Yeast infection symptoms can range from mild to moderate, and include:
- Itching and irritation in the vagina and vulva
- A burning sensation, especially during intercourse or while urinating
- Redness and swelling of the vulva
- Vaginal pain and soreness
- Vaginal rash
- Thick, white, odor-free vaginal discharge with a cottage cheese appearance
- Watery vaginal discharge
Complicated yeast infection
You might have a complicated yeast infection if:
- You have severe signs and symptoms, such as extensive redness, swelling and itching that leads to tears, cracks or sores
- You have four or more yeast infections in a year
- Your infection is caused by a less typical type of fungus
- You’re pregnant
- You have uncontrolled diabetes
- Your immune system is weakened because of certain medications or conditions such as HIV infection
Causes
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:
- Antibiotic use, which causes an imbalance in natural vaginal flora
- Pregnancy
- Uncontrolled diabetes
- An impaired immune system
- Taking oral contraceptives or hormone therapy that increase estrogen levels
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.