Vaginal Yeast Infection

What causes a vaginal yeast infection

Candida normally lives in small numbers in the vagina, mouth and gut, kept in check by lactobacilli bacteria and the immune system. When this balance changes, yeast multiplies.

Common triggers:

• antibiotics: reduce protective bacteria
• pregnancy: high estrogen levels
• hormonal contraception with higher estrogen, or hormone therapy
• uncontrolled diabetes: high sugar levels feed yeast
• weakened immunity: HIV, steroid use, chemotherapy
• warm, moist environment: tight synthetic clothing, wet swimsuits
• irritants: douching, scented products

Symptoms

• intense itching of the vulva and vagina
• burning, especially when urinating
• redness, swelling and soreness of the vulva
• small cracks or cuts in the skin
• thick, white, clumpy discharge, like cottage cheese, usually odorless; sometimes thin and watery
• pain during sex

Yeast infection vs other causes

Many women who self-diagnose a yeast infection actually have bacterial vaginosis or another condition, so get tested if unsure. Skin conditions such as lichen sclerosus and contact dermatitis can also cause itching.

Diagnosis

A clinician can diagnose a yeast infection by:

• examining the vulva and vagina
• testing vaginal pH
• looking at a sample of discharge under a microscope for yeast
• culture or PCR testing for recurrent or treatment-resistant infections, to identify the yeast species

Treatment

Uncomplicated infections

• Over-the-counter antifungal creams or suppositories (clotrimazole, miconazole, tioconazole), used for 1, 3 or 7 days, following the label. They are equally effective; shorter courses use stronger doses.
• Prescription oral fluconazole as a single tablet.
• Symptoms usually improve within 2 to 3 days and clear within a week.

Complicated or severe infections

• longer courses of topical treatment (7 to 14 days)
• repeat fluconazole doses as prescribed
• non-albicans species (such as Candida glabrata) may need boric acid suppositories or other antifungals; boric acid must never be swallowed

Pregnancy

Use a 7-day vaginal antifungal cream or suppository. Oral fluconazole is generally avoided in pregnancy. Check with your clinician before treating.

Recurrent vulvovaginal candidiasis

Defined as 3 or more symptomatic infections in a year. Management includes:

• confirming the diagnosis with culture
• an initial longer treatment course, then maintenance antifungal therapy for about 6 months
• newer prescription antifungals in some cases
• checking for and controlling diabetes

Partners

Yeast infections are not considered sexually transmitted, and routine partner treatment is not recommended. Male partners occasionally develop redness and itching of the penis (balanitis) that responds to antifungal cream.

Prevention

• wear breathable cotton underwear and avoid tight clothing
• change out of wet swimsuits and sweaty clothes promptly
• avoid douching and scented products
• take antibiotics only when needed
• control blood sugar if you have diabetes
• evidence for probiotics and yogurt is mixed; they are unlikely to harm

Frequently asked questions

What are the symptoms of a yeast infection?

Typical symptoms are intense vaginal and vulvar itching, burning, redness, swelling, soreness, pain with sex or urination, and a thick, white, odorless discharge that looks like cottage cheese.

How do I get rid of a yeast infection fast?

Over-the-counter antifungal creams or suppositories, or a single prescription fluconazole tablet, usually relieve symptoms within 2 to 3 days. Follow the full course even if you feel better. See a clinician if symptoms do not improve in a week.

How do I know if it's a yeast infection or BV?

Yeast infections usually cause intense itching and thick white discharge without odor. Bacterial vaginosis typically causes a thin, gray discharge with a fishy smell and little itching. A clinic test can tell them apart, which matters because they need different treatments.

Can a yeast infection go away on its own?

Mild yeast infections sometimes clear without treatment, but most need antifungal medicine to resolve symptoms. Treatment is safe, inexpensive and effective, so there is little reason to wait.

Why do I keep getting yeast infections?

Recurrent infections can result from diabetes, frequent antibiotics, hormonal changes, a weakened immune system or resistant Candida species. Sometimes another condition is misdiagnosed as yeast. See a clinician for testing and longer-term treatment if you have 3 or more a year.