Scar is a permanent mark left when an injury on the skin or other part of the body heals. Scars may result from a wound, such as a deep cut, or from a major burn, sore, or surgery. Generally, such injuries damage the dermis (second layer of skin), which contains connective tissue. Damage to only the epidermis (outermost layer of skin), such as a scratch, does not produce a scar.
When an injury heals, new connective tissue forms. Then a new epidermis covers the injured area–the scar. The scar at first is red. The redness in time fades, but the scar may remain white and hairless. The cells that contribute to skin color and hair formation die when the injury occurs. Scars become smaller as they heal and often itch or hurt.
Scars vary according to the area where they form. For example, a cut over the breastbone produces a wider, thicker scar than a similar cut on the face. Sometimes, too much connective tissue forms during healing. This condition results in an elevated scar. It may also produce a keloid, which is a large scar that extends beyond the damaged area. Ugly scars may be corrected by various techniques that hide, flatten, smooth, or elevate the injured area.
