Candidiasis
An infection caused by overgrowth of Candida yeast
Quick Facts
- Type: Fungal (yeast) infection
- Cause: Overgrowth of Candida yeast
- Common sites: Mouth, vagina, skin folds, throat
- Treatment: Antifungal medication
Overview
Candidiasis is an infection caused by an overgrowth of a yeast called Candida. Small amounts of Candida normally live on the skin, in the mouth, in the gut, and in the vagina without causing problems, kept in check by the body's natural balance and immune system. When that balance is disturbed, the yeast can multiply and cause infection.
Candidiasis can affect different parts of the body. Common forms include oral thrush (in the mouth and throat), vaginal yeast infection, and skin infections in warm, moist folds. Most of these are mild and respond well to antifungal treatment. Less commonly, Candida can enter the bloodstream and cause a serious infection, mainly in people who are very ill or have weakened immune systems.
Symptoms
Symptoms depend on where the infection occurs:
- Oral thrush: White patches in the mouth or on the tongue, redness, soreness, and difficulty swallowing.
- Vaginal yeast infection: Itching, burning, redness, and a thick white discharge.
- Skin candidiasis: Red, itchy rash in skin folds such as the groin, under the breasts, or armpits, sometimes with small surrounding spots.
- Esophageal candidiasis: Pain or difficulty swallowing, usually in people with weakened immunity.
Invasive candidiasis, when the yeast spreads to the blood and organs, can cause fever and serious illness and is a medical emergency requiring hospital care.
Causes
Candidiasis develops when conditions allow Candida to overgrow. Common triggers include:
- Antibiotics: They can kill the helpful bacteria that normally keep yeast in check.
- Weakened immunity: From illness, certain medications, or conditions such as HIV.
- Diabetes: Especially when blood sugar is poorly controlled.
- Warmth and moisture: Skin folds, tight clothing, and dampness favor skin infections.
- Hormonal changes: Pregnancy and some hormone treatments can promote vaginal yeast infections.
Risk Factors
- Recent or frequent antibiotic use
- Diabetes, particularly when poorly controlled
- A weakened immune system or use of corticosteroids
- Pregnancy
- Wearing dentures, for oral thrush
- Obesity and excessive sweating, for skin infections
- Being a newborn or very young infant, for oral thrush and diaper rash
Diagnosis
Many forms of candidiasis are diagnosed by their appearance and symptoms. Tests may be used to confirm or guide treatment:
- Physical examination: Often enough for oral thrush, skin infections, and typical vaginal infections.
- Swab or sample: Examined under a microscope or cultured to identify the yeast.
- Blood tests and cultures: When invasive candidiasis is suspected in seriously ill patients.
- Endoscopy: To diagnose esophageal candidiasis when swallowing is painful.
Treatment
Candidiasis is treated with antifungal medicines, with the form and length of treatment depending on the location and severity:
- Topical antifungals: Creams, ointments, or vaginal preparations for skin and many vaginal infections.
- Oral antifungals: Lozenges or liquids for oral thrush, and tablets for more widespread or stubborn infections.
- Intravenous antifungals: For severe or invasive candidiasis treated in the hospital.
- Treating the cause: Controlling diabetes, reviewing antibiotic use, and keeping skin folds clean and dry.
Most localized infections clear with treatment, though they can recur if the underlying trigger remains.
Prevention
- Keep skin clean and dry, especially in folds
- Manage diabetes and keep blood sugar well controlled
- Use antibiotics only when needed
- Practice good oral hygiene and clean dentures, to prevent thrush
- Wear breathable clothing and change out of damp clothes promptly
- Rinse the mouth after using inhaled corticosteroids
When to See a Doctor
See a doctor if you have symptoms of a yeast infection that do not improve with treatment, that keep coming back, or if you are unsure of the diagnosis. People with diabetes or a weakened immune system should seek care promptly. Get urgent medical attention if you have a high fever with chills and feel seriously unwell, or trouble swallowing, since these may indicate a more serious or invasive infection that needs immediate treatment.
Frequently Asked Questions
What causes candidiasis?
Candidiasis is caused by an overgrowth of Candida yeast, which normally lives harmlessly on the body. Triggers include antibiotics, a weakened immune system, diabetes, warm and moist skin folds, and hormonal changes such as pregnancy.
Is candidiasis contagious?
Most common forms, such as vaginal and skin yeast infections, are not considered contagious in the usual sense, because Candida is already present on the body. However, it can sometimes be passed between people in certain situations, such as oral thrush in infants and breastfeeding mothers.
How is candidiasis treated?
It is treated with antifungal medicines. Skin and many vaginal infections respond to creams or vaginal preparations, oral thrush to lozenges or liquids, and more widespread infections to antifungal tablets. Severe or invasive infections need hospital treatment.
Why do yeast infections keep coming back?
Recurrent infections often happen when an underlying trigger remains, such as poorly controlled diabetes, repeated antibiotic use, or a weakened immune system. Addressing the cause, along with treatment, helps reduce recurrences.
When is candidiasis serious?
Most candidiasis is mild and localized. It becomes serious when Candida spreads into the bloodstream or organs, called invasive candidiasis, mainly in very ill or immunocompromised people. High fever, severe illness, or trouble swallowing warrant urgent care.
References
- Centers for Disease Control and Prevention (CDC). Candidiasis.
- MedlinePlus, U.S. National Library of Medicine. Yeast infections.
- Mayo Clinic. Oral thrush — Symptoms and causes.
- Cleveland Clinic. Candidiasis.