What are the yellow streaks under the nail plate indicative of?

The presence of yellow streaks under the nail plate is indicative of onychomycosis, which is a fungal infection of the nails. This condition often results in discoloration, thickening, and distortion of the nail structure. The yellowing often occurs as the fungal organism grows and spreads within the nail, leading to a change in appearance. Onychomycosis can affect any part of the nail but commonly manifests through yellow streaks or patches underneath the nail plate, as well as potential brittleness and flaking.

Healthy nails should appear clear and smooth without any discoloration, while onycholysis refers to the separation of the nail from the nail bed, typically not associated with yellow streaks under the nail. Thickened nails may occur for various reasons, including trauma or fungal infections, but they do not specifically indicate yellow streaks. Understanding these characteristics helps in the identification and treatment of nail conditions.