Carpal tunnel syndrome refers to the symptoms and signs of sensory and motor dysfunction caused by compression of the ulnar nerve in the carpal tunnel of the wrist due to any factor. The carpal tunnel is also known as Guyon's canal, located on the ulnar side of the anterior wrist area, formed by the common part of the transverse carpal ligament and the distal part of the palmar carpal ligament. The canal contains the ulnar artery, ulnar vein, and ulnar nerve passing through it. Inside the canal, the ulnar nerve divides into deep and superficial branches, that is, motor branches and sensory branches. The upper mouth of the carpal tunnel is formed by the proximal margin of the pisiform bone, the palmar carpal ligament, and the transverse carpal ligament; the lower mouth of the carpal tunnel is formed by the palmar carpal ligament, the short palmar muscle and fascia, the pisohamate ligament, the ulnar flexor carpal tendon, and the tendons of the intrinsic muscles of the hand.