A fungal infection, or mycosis, is an adverse condition caused by pathogenic fungi colonizing host tissues. These infections are broadly categorized based on the site and depth of colonization, ranging from superficial infections on the skin and nails to deep systemic mycoses that can affect internal organs. Etiological agents include various molds and yeasts. Diagnosis is typically established through clinical signs, direct microscopy, or fungal culture. Treatment protocols are highly dependent on the type and severity of the infection, generally involving antifungal pharmaceuticals, topical agents, or systemic therapies designed to inhibit fungal cell wall synthesis or membrane integrity. Management often requires careful determination of the causative species to ensure appropriate targeted antifungal coverage.