What is a characteristic of a nail fungus?

A key characteristic of a nail fungus is the discoloration and thickening of the nail plate. Fungal infections often manifest as changes in the appearance of the nails, where the infected nail may become yellow, brown, or even greenish in color. This discoloration occurs due to the accumulation of debris between the nail and the nail bed, as well as the growth of the fungus itself. In addition to color changes, the nail may also thicken as a result of inflammation and the body's response to the infection. This thickening can make the nail appear distorted or brittle, further indicating the presence of a fungal infection.

Other options, while related to nail health, are not specific indicators of a fungal infection. For example, while aching pain may occur due to various nail conditions or injuries, it is not a definitive sign of a nail fungus. Increased flexibility of the nail is typically associated with other issues, such as moisture exposure or weak nail structure, rather than fungal infections. Similarly, a reduction in nail length can occur for many reasons, but it is not a primary symptom of fungal infections. Thus, the distinctive signs of discoloration and thickening make them hallmark characteristics of nail fungus.