After an injury to the skin, the body sends cells to the wound that can build new skin and tissue. After it stops bleeding, a scab develops. During the first few weeks, natural collagen fills in the gap around and under the scab, forming new skin – a scar. Normal scar tissue slowly grows thicker and then smoother. Collagen production stops after a few weeks. Capillaries form to deliver blood to the injured area, helping it to heal more quickly. The scar isn’t quite as strong as the original skin. It becomes flat and takes on a skin color closer to that of the surrounding area. Abnormal scar tissue, such as hypertrophic or keloid, may never completely heal or fade without additional scar treatment.