Which condition describes brittle nails?

Brittle nails are commonly described by the condition known as onychorrhexis. This term refers specifically to the presence of longitudinal ridges or splits in the nails, which can lead to fragility and breakage. The nails may appear thin and brittle, making them more susceptible to chipping and splitting.

Understanding the other terms can help clarify why they do not describe brittle nails. Onychomycosis refers to a fungal infection of the nails that leads to discoloration and thickening, but it does not specifically indicate brittleness. Leuconychia describes white spots or lines on the nails, typically resulting from trauma or lack of nutrition, but this condition does not address the brittleness aspect. Onycholysis involves the separation of the nail from the nail bed but does not specifically indicate a brittle condition either.

Therefore, onychorrhexis distinctly identifies the characteristics associated with brittle nails, making it the correct choice.