Nail deformation, nails or toenails changed shape, hardness, thickness, color, etc. Changed. The surface is uneven, yellow spots appear under the deck, gradually thickening Or hollowed out and incomplete. The thickening of the edge of the nail is especially thick, and the original luster is lost and gray. White, nails become brittle, powdery shedding or defect. Most people are accompanied by plantar moisture.