Fungal infections of the oral cavity, known as candidiasis, are commonly caused by the yeast Candida albicans. Risk factors include use of antibiotics, corticosteroids, or having a weakened immune system from diseases like HIV/AIDS or diabetes. Candidiasis ranges from mild to severe and can be classified as mucocutaneous (infecting the mouth and skin) or systemic (infecting multiple organs). Diagnosis involves examining clinical samples under a microscope for fungal hyphae or culturing samples on agar plates to grow Candida colonies.