The nail is one of the attachments to the skin. Has its specific function. First of all, it has a "shield effect, which can protect the distal abdomen from damage. Maintain its stability. Enhance the sensitivity of finger touch. Help the hand to grasp, lick, pinch, squeeze, etc. The blood supply of the nail bed is rich, and the blood supply is regulated. The role of body temperature. Secondly, nails are the focus of hand beauty, beautiful nails add feminine charm. Nail defects or deformed patients. Even if he (she) has a well-functioning finger, due to the nails he (she ) It is possible to hide the finger because of inferiority and not use it, so that the function is abolished.