Which condition refers to a fungus affecting the nails?

Onychomycosis is the term specifically used to describe a fungal infection that affects the nails. This condition is caused by various types of fungi and can lead to symptoms such as discoloration, thickening, and crumbling of the nail. The diagnosis is essential for proper treatment and management, as antifungal medications may be necessary to eliminate the infection.

Other terms listed refer to different nail conditions. For example, onychosis is a general term that encompasses any disease or disorder of the nails and does not specify a fungal origin. Onychia refers to inflammation of the nail matrix, often related to an infection but not limited to fungal causes. Agnail, also known as hangnail, describes the painful condition where a small piece of skin near the nail bed tears. Understanding these distinctions helps in identifying and treating nail conditions effectively.