The nerves of the hand include the median, ulnar and radial nerves. If the nerves of the hand are severed or damaged, there will be loss of skin sensation in the corresponding innervated area and dysfunction of innervation in the motor area. If the median nerve is damaged, the thumb, index finger, middle finger, ring finger near the middle finger side and palm near the thumb side of the sensory numbness, thumb to palm dysfunction; if the ulnar nerve is damaged, the pinky finger, ring finger near the pinky side of the palm, the small fisheye muscle skin sensory numbness, the pinky finger and ring finger straightening obstacles, and syndactyly, splitting the finger abnormalities; if the radial nerve is damaged, the manifestation of the tiger’s mouth skin sensory abnormality.