Surgeons are always dealing with wounds, whether they are wounds caused by trauma or wounds caused by the need to treat a disease for surgery. Injuries can involve various tissues and organs of the body, including internal organs, bones, nerves, etc. Today, we will talk about the healing of superficial wounds. How do wounds heal? Before talking about wound healing, let’s talk about the tissue structure of the body surface, because wound healing is the process of repairing the damaged tissue structure. The tissue structure of the body surface is firstly the skin, below the skin is the subcutaneous tissue, mainly the fibrous tissue layer and the fat cell layer, and deeper on the tendon and muscle layer. Superficial wounds generally involve only the skin and subcutaneous tissue layer, and the skin can be simply divided into epidermis and dermis, these tissues are rich in capillary network, these capillary network is like a sponge that absorbs enough water, even if it is a superficial abrasion, there will be fresh blood oozing, so the wound is first manifested as bleeding, generally it is the capillary network of these tissues is destroyed by the oozing blood, while triggering the hemostatic process of the body . So from the beginning of bleeding, the wound repair process also starts at the same time. The capillary network that is bleeding contracts and forms microthrombi to stop the leakage of blood, followed by the exudation of inflammatory cells and inflammatory factors from the tissues, followed by capillary proliferation and formation of granulation tissue, fibroblasts become active, epidermal cells proliferate to cover the wound, fibroblasts proliferate to form and granulation tissue degenerates to form tougher tissue, which is scar tissue, thus linking the tissues on both sides of the wound, and wound healing Completion.