Candida is a yeast (fungus) that lives naturally on the skin and inside the body. Candidiasis develops when the body's microbial balance is disrupted and Candida overgrows, causing infections ranging from oral thrush and vaginal yeast infections to invasive systemic disease.
Medically reviewed by Dr. Qiao Yufei, MD
This guide explains what causes candidiasis, how it spreads between partners, the symptoms by site, how it is diagnosed and treated, and how to reduce your risk. Although Candida is included in our broader STDs in Singapore overview because it is commonly checked alongside other genital infections, it is not strictly classed as a sexually transmitted infection.
Candidiasis is an infection caused by the yeast (fungus) Candida. More than 20 species of Candida can cause infection in humans, with Candida albicans being the most common. Candida normally lives harmlessly on skin and in the mouth, throat, gut, and vagina, kept in check by other microorganisms.
Different sites produce different forms of infection: oral thrush (mouth and throat), vaginal candidiasis (yeast infection), cutaneous candidiasis (skin folds), and invasive candidiasis (a serious bloodstream and organ infection). According to the US Centers for Disease Control and Prevention (CDC), vaginal candidiasis is one of the most common reasons women see a doctor.
Candidiasis develops when something disturbs the body's normal microbial balance, allowing Candida to multiply. It is primarily an overgrowth of yeast already present in the body, rather than a new infection caught from someone else.
Candida is not classified as a sexually transmitted infection in the strict sense, but it can be passed in some situations:
Symptoms vary by location. The four most common presentations are:
White patches on tongue, inner cheeks, palate, gums, or tonsils. Soreness or redness in the mouth. Difficulty or discomfort swallowing.
Itching and irritation of the vagina and vulva. Thick, white, odourless discharge. Redness and swelling. Pain during intercourse or urination.
Red, itchy rash in moist warm areas: armpits, groin, under the breasts, between fingers and toes.
Fever and chills that do not improve with antibiotics. Can affect blood, heart, brain, eyes, and bones. More common in hospitalised or immunocompromised patients.
Diagnosis depends on the affected site. At Mediway Medical Centre, the appropriate test is selected based on your symptoms and the area involved:
Treatment depends on location and severity, and uses antifungal medication rather than antibiotics:
Most uncomplicated cases respond well to a short course of topical or oral antifungal therapy. Recurrent or treatment-resistant cases may need longer suppressive courses or culture-guided drug selection.
Most uncomplicated candidiasis resolves with treatment, but untreated or undertreated infections can cause:
If you have persistent oral patches, recurring vaginal symptoms, or unexplained fevers that do not respond to antibiotics, see a doctor for assessment.
Candida infections occur when the body's microbial balance is disrupted and the fungus overgrows. Common contributors include antibiotic use, weakened immunity (HIV/AIDS, cancer treatment, organ transplant), poorly controlled diabetes, hormonal changes such as pregnancy, and excessive moisture or poor hygiene in skin folds.
Symptoms vary by type and location. Oral thrush causes white patches and mouth soreness. Vaginal candidiasis causes itching, thick white discharge, and pain during intercourse. Cutaneous candidiasis causes red itchy rashes in skin folds. Invasive candidiasis causes fever and chills not responding to antibiotics, mainly in hospitalised or immunocompromised patients.
Diagnosis depends on the affected area and may include physical examination, microscopic examination of cell samples, fungal culture to identify the specific Candida species, and blood tests for suspected invasive candidiasis.
Candida is not classified as a sexually transmitted infection in the strict sense, but it can pass between partners through genital contact. It can also pass from mother to baby during childbirth, and via shared personal items in close-contact settings.
Untreated candidiasis can lead to chronic or recurrent infections, spread to other parts of the body, and in serious cases systemic (invasive) candidiasis, which can be life-threatening for immunocompromised patients.
Treatment depends on location and severity. Topical antifungals (creams, ointments, pessaries such as clotrimazole or miconazole) for skin or vaginal infections. Oral antifungals (fluconazole, itraconazole) for oral thrush or more extensive infections. Intravenous antifungals (amphotericin B, echinocandins) for invasive candidiasis.
Keep skin dry and well-ventilated, manage underlying conditions like diabetes, avoid unnecessary antibiotic use, wear loose breathable clothing, and support immune function with a balanced diet and lifestyle.
References: CDC: About candidiasis · CDC: Invasive candidiasis · HealthHub Singapore
This page is for educational purposes only and does not constitute medical advice, diagnosis, or treatment. Consult a qualified healthcare professional for diagnosis and treatment of suspected candidiasis.