It can be said that “there are no identical scars in the world”, different people have different scars, and even the same person has different scars in different locations, so what is the reason for this? The main factors affecting scars are personal body type, location of the injury, size and depth of the wound, skin tension, whether the wound is infected, etc. Individual body type is a very important factor in the size of scars, people with different body types have different skin characteristics, there is a term called “scar body”, after these people are injured, the scars formed are bigger than normal people, that is to say, in the same area, the same wound, each person formed different scars, because they body constitution is different. This situation is somewhat similar to the “allergy” of people who are prone to allergies. For example, the mucous membrane in our mouth has a very strong healing ability, so our mouth ulcers and skin cracks in the mouth hardly form scars after healing. The size and depth of the wound are also important factors affecting scar tissue, which is well understood. The smaller the trauma area and the more shallow the depth, obviously the smaller the scar will be. If the trauma is very large and deep, the healing ability is poorer, and even the wound is difficult to heal and requires skin grafting. Skin tension, which may be unfamiliar to you, imagine if the skin is split and the closer it is, the faster the skin grows and the smaller the scar. The farther away the skin is, the less likely it is to crawl over and grow up, the slower the skin will heal and the larger the scar will be. This is why the skin near the joints (e.g. knees, fingers) takes longer to grow firmly and well, and the healing process is generally slower and the scars are generally larger. That’s why it takes longer to remove stitches in these areas as well. Whether the wound is inflamed or infected is also better understood. If the wound is inflamed and infected, the normal tissue may be infected and necrotic and not easy to heal, and if the edges of the wound are irregular, the healing time will be longer and the scar will be bigger.