Scarring after burns can affect your appearance in exposed areas such as the face, and in joint areas can lead to functional disability and lifelong regret. This is why people are always concerned about scarring after a burn injury, and this is a question that burn doctors often answer for their patients. So, does a skin injury leave a scar? If you want to answer this question, you must first understand the normal structure of the skin. The skin is one of the largest and most important organs of the body in terms of weight and area, and it wraps the entire surface of the body. The thickness of the skin varies depending on the location. Normal skin is divided into two layers, the epidermis and the dermis, accompanied by a large number of accessories including hair follicles, sweat glands, sebaceous glands, etc. The epidermis on the surface is mainly composed of various types of cells, which are metabolically active and have frequent turnover of old and new cells, and skin flaking is formed by the shedding of aging cells in this layer. Injuries involving this layer alone are easily repaired and are of good quality after repair, and generally do not cause significant cosmetic changes. The deeper side of the dermis is the dermis, which is rich in connective tissue, collagen fibers, elastic fibers, reticular fibers, etc., forming the skin’s tenacity and elasticity against traction. It contains many cells such as fibroblasts, macrophages, and lymphocytes, which help in increasing the skin’s resistance to infection and immunity. The dermis is rich in capillaries and neuroreceptors that help regulate the temperature sensation of external stimuli. Burns that damage the dermis, or even deeper tissues such as fat and muscle below the dermis, are clinically diagnosed as second or third or even fourth degree burns. The repair process of deep burn wounds is a very complex biological engineering. Sooner or later, the necrotic tissue has to detach from the body, and when it does, the body tries to fill the skin defects formed by the detachment of the necrotic tissue by synthesizing collagen in order to restore the pre-injury form. Unfortunately, the newly formed collagen fibers are not arranged as perfectly as they should be, and some are even excessively produced above the skin, which creates a difference between the scar and the normal skin. The scar tissue differs from normal skin in shape, color, texture, tissue structure, and resistance to tensile forces. In clinical practice, deep burns will definitely leave a scar after healing, which is determined by human physiology. For deep burns, the work to be done from the beginning is how to reduce scarring, not eliminate it. Therefore, the main determinant of whether a burn will leave a scar or not is the depth of the burn. The shallower the depth of the burn, the shorter the healing time and the lighter or even less visible the scarring afterwards. Patients are advised to see a specialist in a timely manner after a burn injury, as proper treatment will result in the least amount of scarring, and early anti-scarring interventions can also effectively reduce the risk of scarring.