The function of nails, human nails as one of the accessories of the skin. Has its specific function. First of all, it has the function of "shield", which can protect the pulp of the distal phalanx from damage, maintain its stability, enhance the sensitivity of finger touch, and assist hands to grasp, hold, pinch and squeeze. The nail bed is rich in blood supply and has the function of regulating peripheral blood supply and body temperature. Secondly, nails are the focus of hand beauty, and beautiful nails add charm to women. A patient with defective or deformed nails may hide his or her fingers from use because of inferiority even if he or she has a well-functioning finger.