What is a vaginal yeast infection and how to prevent it?

Vaginal yeast infection — also called vulvovaginal candidiasis (VVC) — is a common mucosal infection caused by an overgrowth of Candida species, most frequently Candida albicans. Many people with a vulva experience at least one episode during their lifetime; for some it becomes recurrent. This article reviews what a vaginal yeast infection is, why it happens, how it is diagnosed and treated, and practical evidence‑based measures to reduce the risk of future episodes. Clinical guidance from professional bodies (ACOG), and reputable health organizations (Mayo Clinic, Cleveland Clinic, NIH/MedlinePlus) are used to inform recommendations [1–4].

What is vulvovaginal candidiasis?

Vulvovaginal candidiasis is an inflammatory condition of the vulva and vagina caused by Candida fungi. Candida species are part of the normal microbial population in and on the body, including the gastrointestinal tract and, in many people, the lower genital tract. Under physiological conditions the vaginal environment, dominated by Lactobacillus species and maintained at an acidic pH, keeps Candida growth in check. When local or systemic factors disrupt that balance, Candida can overgrow and cause symptomatic infection [1–4].

Candida albicans is the most frequent pathogen. Non‑albicans species (for example, Candida glabrata) are less common but clinically important because they may respond differently to antifungal treatments.

How common is it?

Vulvovaginal candidiasis is very common. Up to 75% of people with a vulva will experience at least one episode in their lifetime, and 40–45% will have two or more episodes. A smaller proportion (about 5–8%) experience recurrent vulvovaginal candidiasis, typically defined as four or more symptomatic episodes in 12 months [1–3].

Pathophysiology (why it happens)

The vagina normally hosts a complex microbiota in which Lactobacillus species produce lactic acid and hydrogen peroxide, maintaining a low pH and inhibiting overgrowth of potential pathogens. Factors that reduce lactobacilli numbers or otherwise alter the vaginal environment can promote Candida overgrowth, including:

Systemic or local antibiotic use that disrupts bacterial flora.
Elevated blood glucose or poorly controlled diabetes.
Pregnancy and hormonal changes that alter the mucosal environment.
Use of systemic or topical corticosteroids or other immunosuppressive therapies.
Genetic and immunologic predispositions in some individuals.
Use of certain contraceptives and devices (some hormonal changes or continuous‑wear devices may be associated).
Local moisture and occlusive clothing that create a warm, moist microenvironment.
Sexual activity may be temporally associated with episodes, but Candida is not considered a sexually transmitted infection in the typical sense; treating an asymptomatic partner is generally not necessary [1–4].

Typical symptoms

Symptoms of vulvovaginal candidiasis are usually localized to the vulva and vagina and can range from mild to severe. Common clinical features include:

Vaginal itching or vulvar pruritus (often marked).
Burning or irritation of the vulva, which may be worse with urination or intercourse.
Abnormal vaginal discharge that is typically described as thick, white, and curd‑like; however, discharge appearance alone is not diagnostic.
Vulvar erythema, swelling and fissuring in more severe cases.
Dysuria limited to external burning while urinating (not bladder infection symptoms such as frequency/urgency or significant pain with voiding).

Systemic symptoms such as fever and chills are not typical and should prompt evaluation for a different or more invasive infection [1–4].

How a clinician makes the diagnosis

Because symptoms overlap with other causes of vaginitis (particularly bacterial vaginosis and trichomoniasis), clinical diagnosis usually involves a focused history and physical examination, with laboratory testing as needed:

Assessment of vaginal pH: pH is usually normal (<4.5) in Candida infections. Elevated pH (>4.5) suggests bacterial vaginosis or trichomoniasis.
Microscopy (wet mount with saline and potassium hydroxide): visualization of budding yeast or pseudohyphae on KOH preparation supports the diagnosis.
Vaginal culture or nucleic acid amplification tests (NAATs): considered when microscopy is negative but suspicion remains, for recurrent disease, or when non‑albicans species are suspected because treatment response may differ.
Point‑of‑care tests and clinic algorithms can facilitate rapid diagnosis, but when symptoms are atypical or recurrent, laboratory confirmation is advisable [1–4].

Importantly, empirical treatment based solely on symptoms may lead to misdiagnosis and inappropriate therapy; seeking health care for recurrent or severe symptoms is recommended.

Differential diagnosis: other causes of vaginitis

Several conditions can mimic a yeast infection. Correct identification matters because treatments differ:

Bacterial vaginosis (BV): usually presents with thin, grayish discharge and a fishy odor; pH typically > 4.5.
Trichomoniasis: often associated with frothy or yellow‑green discharge and vaginal erythema; diagnosed via microscopy or NAAT.
Urinary tract infection (cystitis): produces dysuria, frequency and urgency; symptoms may overlap but UTI involves the urinary tract rather than the vulvovaginal tissues.
Dermatologic conditions (lichen sclerosus, contact dermatitis, psoriasis): may cause vulvar itching and require dermatologic or gynecologic management.
Sexually transmitted infections and other inflammatory conditions: may have overlapping features; testing is guided by clinical context.

Because the wrong treatment (for example, antibiotics for candidiasis) can worsen vaginal flora disturbance, laboratory confirmation is often useful, especially for atypical or recurrent cases [1–4].

Standard treatment options

Treatment is directed at eradicating Candida and relieving symptoms. Options include topical antifungals and oral medication.

Topical antifungals (azole class)

Over‑the‑counter (OTC) topical azoles: clotrimazole and miconazole are available as creams and vaginal suppositories in 1‑, 3‑, or 7‑day regimens. Studies show similar efficacy across most topical azole preparations when used appropriately [2,3].
Prescription topical agents: terconazole is available by prescription and can be used for resistant or recurrent cases.

Oral antifungal

Fluconazole 150 mg oral single dose is an effective and commonly used regimen for uncomplicated VVC in non‑pregnant patients. Some clinicians prescribe additional doses for severe infection (for example, an additional 150 mg dose 72 hours later) [2,3].

Choice between topical and oral therapy depends on patient preference, contraindications, pregnancy status, and severity. Topical agents are effective and avoid systemic exposure. For people who prefer a single oral dose, fluconazole is an option if no contraindications exist.

Important safety considerations

Pregnancy: Topical azole therapy is preferred in pregnancy. Oral fluconazole has been associated with rare congenital anomalies when used repeatedly during pregnancy, so topical agents are recommended as first‑line treatment in pregnant patients [1,2].
Breastfeeding: Topical agents are considered compatible with breastfeeding; discuss use of oral therapy with a clinician if needed.
Drug interactions: Oral fluconazole has potential interactions with other medications; check with a clinician or pharmacist.

For treatment‑resistant disease or suspected non‑albicans species, culture and susceptibility testing may guide therapy because some non‑albicans Candida are less responsive to azoles [1–4].

Management of severe or complicated infections

Severe VVC (marked erythema, edema, erosions, intense symptoms) or complicated cases (recurrent infection, immunosuppression, diabetes, pregnancy) may require tailored therapy:

Severe initial episodes may be treated with topical azole for 7–14 days or oral fluconazole with repeat dosing as clinically indicated.
Recurrent VVC (≥4 episodes/year) is managed in two phases: induction and maintenance suppression. A common regimen is induction therapy to control the acute episode (for example, fluconazole 150 mg orally every 72 hours for three doses or an extended topical azole course), followed by suppressive therapy such as fluconazole 150 mg once weekly for 6 months. After discontinuation of suppressive therapy, many patients experience recurrence, but suppression reduces episode frequency during treatment [2,3].
People with uncontrolled diabetes, HIV, or other immunosuppression may require longer or systemic therapy and specialist input.

Consultation with a gynecologist or infectious disease specialist is appropriate for recurrent, refractory, or atypical presentations [1–4].

Preventing vaginal yeast infections: evidence‑based strategies

Complete prevention is not always possible because Candida is a normal commensal organism. However, several practical measures can reduce the risk of symptomatic episodes.

Use antibiotics judiciously

Antibiotics can disrupt the protective vaginal bacterial flora, lowering lactobacilli and allowing Candida to overgrow. Use systemic antibiotics only when indicated and complete prescribed courses; discuss concerns with your clinician. Where possible and appropriate, narrow‑spectrum agents are preferred.

Maintain good glycemic control if you have diabetes

Hyperglycemia promotes Candida growth. Optimizing blood glucose reduces the risk and frequency of infections.

Prefer breathable, non‑occlusive clothing

Tight synthetic underwear or clothing can trap moisture and heat. Choose cotton underwear and avoid prolonged wearing of wet clothing (for example, swimsuits or sweaty athletic wear).

Avoid douching and scented products

Douching disrupts the normal vaginal microbiota and is associated with a higher risk of vaginitis. Similarly, fragranced soaps, sprays, and certain feminine hygiene products can irritate mucosa and alter flora; use mild, unscented cleansers and avoid inserting cleansers or agents into the vagina.

Modify behaviors that increase local moisture

Change out of wet swimsuits or exercise clothing promptly. Use only plain water and a gentle soap for external cleansing of the vulva.

Be cautious with intra‑vaginal products and spermicides

Some spermicides and intravaginal devices may change the local environment. Discuss contraceptive options and vaginal device use with your clinician if you experience recurrent episodes.

Consider modifications related to sexual activity

Candida is not classified as a typical sexually transmitted infection, and routine partner treatment is not recommended if partners are asymptomatic. If a partner has symptoms of infection, evaluation and treatment may be appropriate. Use of barrier contraception will not reliably prevent vaginal candidiasis, though it can protect against sexually transmitted infections.

Probiotics and diet: limited evidence

Interest in probiotics (oral or intravaginal Lactobacillus preparations) for prevention of recurrent vaginitis exists, but evidence is mixed. Some trials suggest modest benefit with certain probiotic strains, but high‑quality data are limited and routine use is not uniformly recommended. Discuss probiotics with your clinician if you wish to try them [1–4].

Address modifiable medical contributors

Review corticosteroid use, immunosuppressive therapy, or other medications with your prescribing clinician when recurrent infections occur. Evaluate for and treat uncontrolled metabolic conditions such as diabetes.

Early recognition and appropriate treatment

Prompt diagnosis and effective treatment of initial symptomatic episodes can reduce the duration of symptoms and may lower the chance of complications or recurrence.

Special populations and considerations

Pregnancy

Yeast infections are more common during pregnancy. Topical azole therapy is the preferred treatment during pregnancy due to concerns about systemic azoles. Always consult an obstetric clinician if symptoms develop [1,2].

People with diabetes

Poor glycemic control increases risk. Optimize diabetes management and seek early treatment for symptomatic episodes.

Immunocompromised individuals

People receiving immunosuppressive therapy or with advanced HIV may experience more severe or recurrent disease and may need specialist management.

Recurrent or refractory cases

Recurrent VVC warrants confirmatory testing (culture, NAAT) to identify species and guide therapy. Consider evaluation for underlying conditions such as diabetes, HIV, or medication‑related immunosuppression.

When to see a clinician

Seek medical care if any of the following apply:

First episode of vulvovaginal symptoms.
Symptoms that are severe, persistent, or atypical.
More than three or four episodes in a 12‑month period (recurrent VVC).
Symptoms do not respond to initial appropriate over‑the‑counter therapy.
Associated systemic symptoms such as fever, pelvic pain, or heavy bleeding.
Pregnancy.
Uncontrolled medical conditions such as diabetes or known immunosuppression.

A clinician can confirm the diagnosis, rule out alternative causes, obtain cultures if indicated, and recommend an individualized treatment and prevention plan [1–4].

Practical home care during an episode

Use prescribed or appropriate OTC antifungal therapy as directed. For topical regimens, complete the full course even when symptoms improve.
Apply cool compresses to the vulva to relieve discomfort; avoid irritants.
Wear loose, breathable clothing and cotton underwear.
Avoid sexual activity until symptoms resolve, or use condoms to reduce friction and irritation if sexual activity occurs.
Refrain from douching or using scented products.

Potential complications

Uncomplicated vulvovaginal candidiasis rarely leads to systemic complications in otherwise healthy people. However, untreated severe infection can cause marked mucosal inflammation, fissuring, and significant discomfort. In people with immunosuppression, Candida can rarely invade more deeply and cause systemic disease, which requires urgent medical attention.

Recurrent infections can have a negative effect on quality of life and sexual health; addressing modifiable risk factors and working with a clinician on suppressive therapy when indicated can improve outcomes.

Summary

Vulvovaginal candidiasis is a common mucosal infection caused by Candida overgrowth. Typical symptoms include vulvar itching, burning, and thick white discharge. Diagnosis is based on clinical assessment and, when needed, microscopy or culture. First‑line treatments include topical azole antifungals and, for many non‑pregnant individuals, a single oral dose of fluconazole. Pregnancy, recurrent disease, diabetes, and immunosuppression require special consideration and often prefer topical therapy or specialist input. Preventive measures focus on minimizing factors that disturb normal vaginal flora: judicious antibiotic use, optimized diabetes control, avoiding douching and scented products, wearing breathable underwear, and prompt treatment of symptomatic episodes. For recurrent or severe disease, consult a clinician for targeted testing and individualized management [1–4].

References

American College of Obstetricians and Gynecologists (ACOG). Vaginal Yeast Infections (Patient FAQs). Available from: https://www.acog.org/womens-health/faqs/vaginal-yeast-infections

Mayo Clinic. Vaginal yeast infection — Symptoms and causes. Available from: https://www.mayoclinic.org/diseases-conditions/vaginal-yeast-infection/symptoms-causes/syc-20377495

MedlinePlus (U.S. National Library of Medicine / NIH). Yeast infection — Vaginal. Available from: https://medlineplus.gov/yeastinfections.html

Cleveland Clinic. Yeast Infection (Vaginal): Symptoms, Causes, and Treatment. Available from: https://my.clevelandclinic.org/health/diseases/21537-yeast-infection-vaginal

(Providers and patients should use these resources for patient education and follow the individualized recommendations of their health care professional.)