Yeast Infection Overview: Causes, Treatments, and Prevention

Vulvovaginal candidiasis, commonly known as a yeast infection, is a fungal infection caused by an overgrowth of Candida species — most often Candida albicans. It affects an estimated 75% of women at least once in their lifetime, and 40–45% will experience two or more episodes. While rarely serious, yeast infections cause significant discomfort and can disrupt daily life. This article reviews the causes, symptoms, treatment options, and prevention strategies based on current clinical guidelines.

What Is a Yeast Infection?

A vaginal yeast infection is a fungal infection that causes irritation, discharge, and intense itching of the vagina and vulva. The condition occurs when Candida, a yeast that normally lives in small amounts in the vagina, grows out of control. Lactobacillus bacteria typically keep Candida in check, but when this balance is disrupted — whether by antibiotics, hormonal changes, or other factors — yeast can multiply and cause symptoms.

According to the Centers for Disease Control and Prevention (CDC), candidiasis is one of the most common fungal infections in the United States. The vast majority of cases are uncomplicated and respond well to short-course antifungal therapy.

Common Causes and Risk Factors

Several factors can disturb the vaginal microbiome and increase the risk of a yeast infection:

• Antibiotic use — Broad-spectrum antibiotics kill protective lactobacilli along with harmful bacteria, allowing yeast to overgrow.
• Elevated estrogen levels — Pregnancy, hormonal birth control, and hormone therapy raise estrogen, which can promote yeast growth.
• Unmanaged diabetes — High blood sugar levels provide a fuel source for Candida.
• Weakened immune system — HIV, corticosteroid therapy, chemotherapy, and other immunosuppressive conditions increase susceptibility.
• Hygiene habits — Douching, scented feminine products, and prolonged moisture (tight clothing, wet swimwear) can disrupt the vaginal environment.

The Mayo Clinic notes that most uncomplicated yeast infections have no identifiable precipitating factor, meaning they can occur in otherwise healthy women without any obvious trigger.

Recognizing the Symptoms

Yeast infection symptoms range from mild to moderate and may include:

• Vulvar itching, soreness, and irritation
• Burning sensation — especially during intercourse or urination
• Redness and swelling of the vulva
• Thick, white, odorless vaginal discharge resembling cottage cheese
• Vaginal pain and tenderness

Severe infections may involve extensive erythema, edema, fissures, and excoriation. According to the CDC, none of these symptoms alone is specific to candidiasis; other conditions such as bacterial vaginosis (BV) and trichomoniasis can present similarly, underscoring the value of laboratory confirmation before treatment.

Diagnosis: When to See a Provider

While many women attempt self-diagnosis, studies show that two out of three women who purchase OTC yeast infection medication do not actually have a yeast infection. Symptoms of BV, chlamydia, gonorrhea, and trichomoniasis can mimic candidiasis. The CDC recommends that any woman whose symptoms persist after OTC treatment, or who has a recurrence of symptoms within two months, be evaluated clinically.

Diagnosis typically involves a pelvic exam, pH testing (vaginal pH is normal, <4.5, in candidiasis), and microscopic examination of a vaginal wet mount with 10% potassium hydroxide (KOH) to visualize yeast or pseudohyphae. Vaginal culture or PCR may be used when microscopy is negative but symptoms persist.

Over-the-Counter Treatment Options

For uncomplicated yeast infections, short-course topical antifungals are highly effective. Available OTC options include:

• Clotrimazole (Gyne-Lotrimin) — 1-, 3-, or 7-day regimens
• Miconazole (Monistat) — 1-, 3-, or 7-day regimens
• Tioconazole (Vagistat) — single-dose ointment

These medications come as creams, ointments, tablets, or suppositories inserted vaginally. Clinical cure rates with azole therapy reach 80–90% in women who complete treatment. The Harvard Health Publishing advises that self-treatment is reasonable for women who have had a previous yeast infection and recognize the symptoms, but a one-time visit to confirm the diagnosis is still recommended.

Important: OTC antifungal creams and suppositories are oil-based and can weaken latex condoms and diaphragms. Patients should consult product labeling for guidance.

Prescription Treatments

For women who prefer oral therapy or who have more severe symptoms, prescription options include:

• Fluconazole (Diflucan) — A single 150 mg oral dose is the most commonly prescribed treatment. For severe symptoms, a second dose may be given 72 hours later.
• Ibrexafungerp (Brexafemme) — FDA-approved in 2021, this oral triterpenoid antifungal offers an alternative for infections that do not respond to azoles.
• Oteseconazole (Vivjoa) — Approved for recurrent vulvovaginal candidiasis in women who are not of reproductive potential; taken orally.

For complicated infections — defined as severe symptoms, recurrent episodes (>4 per year), pregnancy, diabetes, immunosuppression, or non-albicans species — longer courses of therapy (7–14 days of topical or multiple sequential doses of fluconazole) are indicated. Boric acid capsules (600 mg intravaginally once daily for 3 weeks) may be used for azole-resistant cases, though this should not be used during pregnancy.

Treatment Comparison Table

Treatment	Form	Regimen	Availability	Pregnancy Safe	Cure Rate
Clotrimazole	Vaginal cream/suppository	1–7 days	OTC	Yes	80–90%
Miconazole	Vaginal cream/suppository	1–7 days	OTC	Yes	80–90%
Fluconazole	Oral tablet	Single 150 mg dose	Prescription	No	80–90%
Ibrexafungerp	Oral tablet	Two doses in one day	Prescription	Limited data	~75%
Boric acid	Vaginal capsule	600 mg x 14–21 days	Prescription/Compounding	No	~70%
Terconazole	Vaginal cream/suppository	3–7 days	Prescription	Yes	80–90%

Recurrent Yeast Infections

Recurrent vulvovaginal candidiasis (RVVC) is defined as three or more symptomatic episodes within 12 months. It affects approximately 5% of women and carries a substantial quality-of-life and economic burden. RVVC may be idiopathic or secondary to underlying conditions such as frequent antibiotic use, unmanaged diabetes, or immunosuppression.

Management of RVVC involves two phases: induction therapy to achieve mycologic remission (e.g., 7–14 days of topical therapy or three doses of fluconazole 72 hours apart), followed by a six-month maintenance regimen. The standard maintenance regimen is oral fluconazole (100, 150, or 200 mg) once weekly for six months. Topical maintenance alternatives are available when oral therapy is not suitable.

The National Institutes of Health (NIH) notes that suppressive maintenance therapy is effective at controlling RVVC but is rarely curative long-term. Research into vaccines for RVVC is ongoing.

Prevention Strategies

Evidence-based strategies to reduce the risk of yeast infections include:

• Wear cotton underwear and breathable clothing
• Avoid douching and scented feminine products (bubble bath, sprays, pads, tampons)
• Change out of wet clothing (swimsuits, workout gear) promptly
• Use antibiotics only when prescribed and exactly as directed
• Maintain good blood sugar control if diabetic

The CDC emphasizes that probiotics have not been conclusively shown to prevent or treat vaginal yeast infections, despite their popularity. Similarly, home remedies such as garlic cloves, tea tree oil, or yogurt tampons lack sufficient evidence and may cause mucosal irritation.

Yeast Infection During Pregnancy

Yeast infections are more common during pregnancy due to hormonal shifts that alter the vaginal microbiome. Topical azole therapies (clotrimazole, miconazole, terconazole) are considered safe throughout pregnancy. Oral fluconazole, however, is not recommended — especially in the first trimester — due to a potential association with birth defects. Pregnant women with yeast infection symptoms should consult their obstetric provider before using any medication.

Frequently Asked Questions

Can a yeast infection go away on its own?
Mild yeast infections may resolve without treatment in some cases, but most require antifungal medication. Treatment shortens symptom duration and reduces the risk of complications.

Can I have sex with a yeast infection?
Sexual activity is not recommended during treatment, as it may worsen irritation, cause pain, and reduce the effectiveness of vaginal medications. Additionally, OTC creams can weaken condoms.

Are yeast infections sexually transmitted?
Yeast infections are not classified as sexually transmitted infections (STIs), though they can rarely be transmitted between partners. Male partners with symptoms (redness, itching, rash on the penis) should be evaluated.

When should I see a doctor?
See a provider if this is your first infection, you are pregnant, you have recurrent episodes, symptoms are severe, or OTC treatment has not resolved symptoms within a few days.

For further reading, consult the CDC STI Treatment Guidelines for Vulvovaginal Candidiasis, the Mayo Clinic Yeast Infection Overview, the Harvard Health Vaginal Yeast Infection Guide, and the NIH/NCBI Bookshelf Consumer Summary.

This article is for informational purposes only and does not constitute professional medical advice. Always consult a qualified healthcare provider for diagnosis and treatment specific to your situation.