Candidiasis is caused by an overgrowth of Candida, a type of yeast fungus that normally lives on the skin and inside the body, including areas like the mouth, throat, gut, and vagina. Under normal circumstances, Candida coexists harmlessly with other microorganisms and is controlled by the immune system and competing bacteria. Several factors can cause Candida to grow excessively and lead to candidiasis, including:

• A weakened immune system due to conditions like HIV/AIDS, cancer treatments, or use of steroids and chemotherapy.
• Use of antibiotics, which can kill beneficial bacteria that normally keep Candida growth in check.
• Diabetes, particularly if poorly controlled, which can increase susceptibility.
• Hormonal changes during pregnancy, use of oral contraceptives, or hormone replacement therapy.
• Moist and warm conditions on the skin, such as from wearing wet clothing for a long time or excessive moisture in skin folds.
• Other factors like stress, nutritional deficiencies, infrequent mouth hygiene, and use of inhaled corticosteroids.

Candidiasis can affect different parts of the body, causing oral thrush, vaginal yeast infections, cutaneous candidiasis on the skin, and, in severe cases, invasive infections that enter the bloodstream or internal organs. In summary, candidiasis results from an imbalance between Candida and the body’s normal defenses, often triggered by immune suppression, antibiotics, hormonal changes, or environmental factors favoring yeast growth.