Nail deformation may be related to extrusion, micronutrient deficiency or fungal infection. 1. Extrusion: If the fingernail is extruded or rubbed by hard objects, it may lead to nail deformation, which will generally recover by itself after contacting the causative factors, and attention should be paid to protect the nails. 2. Lack of micronutrients: When a single person lacks calcium, magnesium, zinc and other micronutrients, the nails will be concave, brittle and soft, which can be improved through a reasonable diet or supplementation of micronutrients. 3. Fungal infections: fungal infections can damage the nail plate, resulting in nail deformation, discoloration, thickening, etc., which can be treated by oral itraconazole or terbinafine. There are many factors that cause nail deformation, it is recommended to go to the hospital in a timely manner, after clarifying the cause of the disease, symptomatic treatment.