Tinea Unguium, also known as onychomycosis, is a fungal infection that affects the nails, particularly the toenails and fingernails. It is caused by various types of fungi, including dermatophytes, yeasts, and non-dermatophyte molds. Symptoms may include discoloration, thickening, and brittleness of the nails, which can lead to pain and discomfort. The infection is often more common in individuals with weakened immune systems, poor circulation, or those who frequently expose their feet to damp environments. Treatment options include topical antifungal medications and oral antifungal drugs, depending on the severity of the infection.