Peripheral nerve regeneration occurs spontaneously after injury due to the permissive environment and activation of the intrinsic growth capacity of neurons. Injuries can be divided into three categories: neurapraxia, axonotmesis and neurotmesis. Wallerian degeneration occurs due to axonotmesis and neurotmesis, affecting the axon distal to the site of damage. After this phase is complete, the damaged neurons try to rebuild the damaged fibers with axonal budding. Axonal growth can occur efficiently, which is influenced by signaling molecules and the integrity of the connective tissue tunnel. It can allow axons to grow back in the right direction and innervate the innervation of the target tissue.