Vaginal Yeast Infection (Candidiasis)

What is Yeast infection (vaginal)?

A vaginal yeast infection, medically known as vulvovaginal candidiasis, is an overgrowth of the fungus Candida (most often Candida albicans) in the vagina and vulva. While Candida is a normal part of the vaginal flora, certain conditions allow it to multiply unchecked, leading to inflammation and the classic “yeast infection” symptoms.

Yeast infections are extremely common; the Centers for Disease Control and Prevention (CDC) estimate that up to 75 % of women will experience at least one episode in their lifetime, and about 40–45 % will have recurrent infections (≥4 episodes per year) [1].

Common Causes

Several factors disturb the delicate balance of bacteria and yeast in the vagina, creating an environment where Candida can thrive. The most frequent triggers include:

• Antibiotic use – broad‑spectrum antibiotics kill beneficial lactobacilli, allowing yeast to proliferate.
• Hormonal changes – pregnancy, oral contraceptives, or hormone‑replacement therapy increase estrogen levels, which can promote yeast growth.
• Uncontrolled diabetes – high blood glucose provides food for Candida; especially common in poorly controlled type 1 or type 2 diabetes.
• Elevated vaginal pH – douches, scented feminine products, or a shift in the microbiome raise pH above the normal 3.8–4.5, favoring yeast.
• Immunosuppression – HIV infection, chemotherapy, or chronic steroids weaken the immune response to yeast.
• Moist, warm environments – tight clothing, non‑breathable underwear, or prolonged wearing of wet swimwear can trap moisture.
• Sexual activity – while not classified as a sexually transmitted infection, sexual intercourse can transfer yeast or alter vaginal conditions.
• Dietary factors – high‑sugar or high‑carbohydrate diets may supply extra substrates for Candida growth.
• Stress & lack of sleep – chronic stress can impair immune function and alter hormone balance.
• Use of intra‑uterine devices (IUDs) or other foreign bodies – these can occasionally disrupt normal flora.

Associated Symptoms

Symptoms usually develop gradually and may range from mild irritation to significant discomfort. Common clinical features include:

• Intense itching or burning of the vulva and vagina.
• White, clumpy discharge often described as “cottage‑cheese” consistency; usually odorless.
• Redness, swelling, or soreness of the vulvar skin.
• Sensation of wetness even after wiping.
• Pain or discomfort during sexual intercourse (dyspareunia) or while urinating.
• Rarely, a rash that can spread to the inner thighs or perineum.

Most women experience only a few of these signs, and symptoms can wax and wane over a few days to a week.

When to See a Doctor

While many yeast infections resolve with over‑the‑counter (OTC) therapy, medical evaluation is essential when any of the following occur:

• Symptoms persist beyond 7 days despite treatment.
• Recurrent infections (≥4 episodes per year).
• Unusual discharge color (yellow, green, or bloody) or a strong foul odor.
• Severe pelvic or lower‑abdominal pain, fever, or chills.
• First episode after pregnancy, childbirth, or after starting a new contraceptive method.
• Known diabetes, HIV, or other immunocompromising condition.
• Any doubt about the diagnosis (e.g., possible bacterial vaginosis or sexually transmitted infection).

Prompt evaluation helps rule out other conditions that require different treatment, such as bacterial vaginosis, trichomoniasis, or genital herpes.

Diagnosis

Healthcare providers use a combination of history, physical examination, and laboratory testing:

1. Medical history & symptom review – duration, frequency, recent antibiotics, sexual activity, and medical conditions.
2. Speculum examination – visualization of the vaginal walls and discharge.
3. Microscopic evaluation (wet mount) – a sample of discharge is placed on a slide with saline; under a microscope, budding yeast or pseudohyphae are seen in about 50‑70 % of cases.
4. Culture – the specimen is grown on special media to confirm Candida species; useful for recurrent or treatment‑resistant infections.
5. pH testing – vaginal pH > 4.5 suggests bacterial vaginosis or trichomoniasis rather than candidiasis.
6. Additional tests – in immunocompromised patients, a yeast swab for Candida glabrata or Candida krusei may be ordered, as these species may require different antifungals.

Most uncomplicated cases are diagnosed clinically, but laboratory confirmation becomes important for recurrent or atypical presentations.

Treatment Options

Therapy aims to eradicate the yeast, relieve symptoms, and prevent recurrence. Options fall into two broad categories: medical** (pharmaceutical) and **home/self‑care** measures.