Overview
A yeast infection (vaginal candidiasis or thrush) is a fungal infection of the vagina and vulva caused by an overgrowth of Candida yeast, most commonly Candida albicans. It causes itching, irritation, and a white, cottage cheese-like discharge. It is extremely common and usually responds quickly to antifungal treatment. Oral or skin candida infections can also occur.
How common is it?
About 75% of women will have at least one vaginal yeast infection in their lifetime. Around 40 to 45% will have two or more. Candida infections also commonly affect the mouth (oral thrush) and skin folds.
Causes and risk factors
Candida normally lives in small amounts in the vagina and on skin without causing harm. Overgrowth occurs when the normal balance of the vaginal microbiome is disrupted.
Common risk factors
- Antibiotic use (disrupts normal lactobacillus flora allowing Candida overgrowth)
- Pregnancy (hormonal changes increase glycogen in vaginal cells)
- Uncontrolled diabetes (high glucose promotes Candida growth)
- Immunosuppression (HIV, corticosteroids, chemotherapy)
- High-oestrogen contraceptives
- Tight synthetic underwear and wet clothing (warm, moist environment)
- Douching or using vaginal deodorants
- Sexual transmission (less common — not classified as an STI)
Symptoms
- Intense itching and irritation of the vagina and vulva
- A white, thick, cottage cheese-like vaginal discharge without odour
- Redness and swelling of the vulva
- Burning sensation, especially during urination or sexual intercourse
- Soreness and rash on surrounding skin
- Oral thrush: white patches on the tongue and mouth lining, redness and soreness
When to see a doctor
See a doctor if this is your first yeast infection (to confirm diagnosis), if symptoms do not improve after over-the-counter treatment, if you have 4 or more infections per year (recurrent candidiasis), if you are pregnant, or if symptoms are severe. Recurrent candidiasis requires investigation for underlying causes.
Diagnosis
Typical symptoms may suggest thrush, but other infections can look similar. A clinician may examine the area and take a swab, particularly if symptoms recur or treatment fails. Tests for contributing conditions, including a check for diabetes when appropriate, depend on the history and examination.
Treatments
Antifungal pessaries and cream
Clotrimazole 500mg vaginal pessary (single dose) or clotrimazole cream are available over the counter. Highly effective for uncomplicated vaginal thrush. Use the external cream for vulval symptoms alongside the pessary.
Oral fluconazole
Oral fluconazole is an option for some non-pregnant adults with confirmed vaginal thrush. A pharmacist or prescriber should check suitability and interactions, particularly with other regular medicines. Do not self-treat with oral fluconazole during pregnancy or when trying to conceive; seek advice about a vaginal treatment instead.
Maintenance therapy for recurrent candidiasis
A clinician may prescribe a longer antifungal course for confirmed recurrent thrush, after checking contributing conditions, pregnancy and interactions. The regimen is individualised; symptoms can return after it ends. Do not begin long-term oral fluconazole without assessment.
Self-care and lifestyle
- Wear loose, breathable cotton underwear
- Change out of wet swimwear or gym clothes promptly
- Avoid perfumed soaps, bath products, and vaginal deodorants (disrupt the normal vaginal flora)
- Take prescribed antibiotics as directed. Probiotic yoghurt and supplements are not established treatments for recurrent thrush; seek advice if symptoms return.
Prevention
Wearing breathable underwear, avoiding unnecessary antibiotic use, maintaining good blood glucose control in diabetes, and avoiding douching reduce the risk of vaginal thrush.
Sources for targeted updates
Updated: 24 October 2026. Specific treatment, safety or key-fact statements corrected in this update. This update covers the named sections; a full review of the remaining guide is pending.