Yeast infections, also referred to as candidiasis, are fungal infections caused by an overgrowth of Candida, a type of yeast normally found on the skin and mucous membranes. These infections can range from mild local irritation to serious, systemic health complications. The most common species responsible for yeast infections is Candida albicans, although other types like Candida glabrata and Candida auris may also be involved.

Types of Yeast Infections

Yeast infections can be classified based on their location in the body. They fall into two main categories: local mucocutaneous infections and invasive candidiasis.

Local Mucocutaneous Infections

These are superficial infections affecting the skin, mouth, throat, esophagus, genitals, and other mucous membranes. Common types include:

  • Oral thrush: White patches in the mouth and throat.

  • Vaginal candidiasis: Common in women; causes itching, burning, and discharge.

  • Cutaneous candidiasis: Affects folds of skin such as underarms, under breasts, and groin.

  • Penile yeast infection: Redness, irritation, and white patches on the penis.

These types are generally not life-threatening and can be effectively treated with topical or oral antifungal medications.

Invasive Candidiasis

This severe form occurs when Candida enters the bloodstream or internal organs. The most common type is candidemia, a bloodstream infection. Invasive infections can affect the heart, brain, eyes, bones, and other organs, and are more likely in hospitalized or immunocompromised individuals.

Symptoms

Symptoms vary widely based on the infection type and location:

  • Oral thrush: White patches, redness, soreness, loss of taste

  • Vaginal yeast infection: Itching, thick discharge, discomfort during intercourse or urination

  • Skin infections: Red, itchy, scaly rashes in moist areas

  • Penile yeast infection: Redness, soreness, and white patches

  • Invasive candidiasis: Fever, chills, and no response to antibiotics; may progress to organ-specific symptoms

Causes and Risk Factors

Yeast infections develop when conditions favor the overgrowth of Candida. Contributing factors include:

  • Antibiotics: Disruption of healthy microbiota

  • Weakened immune system: HIV/AIDS, cancer, organ transplants

  • Hormonal changes: Pregnancy, birth control pills

  • Diabetes: High blood sugar supports yeast growth

  • Poor hygiene or damp clothing

  • Dry mouth or poor oral health

  • Use of corticosteroids or chemotherapy

Anyone can get a yeast infection, but immunocompromised individuals are at greater risk for systemic infections.

Diagnosis

Diagnosis depends on the infection site:

  • Physical examination: Identification of visible symptoms

  • Swab tests: Oral, vaginal, or skin swabs for culture

  • Blood tests: For suspected systemic infections

  • Endoscopy or biopsy: For esophageal or deep tissue involvement

In many cases, healthcare providers begin treatment based on symptoms without waiting for lab results.

Treatment Options

Treatment varies based on severity and location:

Topical Antifungals

  • Miconazole (Monistat)

  • Clotrimazole (Lotrimin)

  • Nystatin (for oral infections)

Oral Antifungals

  • Fluconazole (Diflucan)

  • Itraconazole (Sporanox)

Intravenous Antifungals

  • Used for invasive candidiasis

  • Includes echinocandins like caspofungin or micafungin

Some individuals with recurring infections may need long-term preventive therapy or alternative treatments.

Prevention

Prevention strategies depend on the type and recurrence of infection:

  • Good hygiene: Daily washing and drying of skin folds

  • Proper denture care: For preventing oral thrush

  • Rinsing mouth after inhaled corticosteroids

  • Limit sugar intake: Yeast feeds on sugar

  • Wearing breathable fabrics: Prevents moisture buildup

  • Probiotics: Help balance gut flora

  • Medical supervision: In high-risk hospital settings, prophylactic antifungals may be used

Related Conditions

Several health conditions increase the risk of developing yeast infections:

  • HIV/AIDS: Major immunosuppressive condition

  • Diabetes mellitus: Poor glucose control increases susceptibility

  • Cancer: Especially during chemotherapy

  • Organ transplants: Due to use of immunosuppressive drugs

Living With Yeast Infections

While most superficial yeast infections resolve with proper treatment, recurrent or systemic infections require ongoing management. If left untreated, invasive infections can become life-threatening.

Patients should:

  • Complete all prescribed medications

  • Avoid irritants like perfumed soaps

  • Follow up with healthcare providers for recurring symptoms

  • Maintain a healthy diet and lifestyle

With medical guidance, most people recover fully from yeast infections and can take steps to avoid recurrence.