When recovering from an injury, trauma or skin condition, scarring is a natural part of the healing process. If the trauma involves the most superficial layers of the skin (epidermis and superficial dermis), you can heal without scarring. However, if the trauma involves the deep dermis, a scar will develop. Scars can be atrophic (indented), hypertrophic (raised), keloid (raised, red and large), pigmented or a combination of these characteristics.
Scarring naturally follows acne, injuries or surgery. The most common scar type is an indented scar, which is often left by acne on the face, chest or back.