Scars are fibrous tissue that forms when the body repairs damaged skin. Unlike normal skin with its organized layers of epidermis, dermis, and subcutaneous tissue, scar tissue has a different structure with disorganized collagen fibers that create the characteristic appearance we recognize as scars.
When skin is injured, the body immediately initiates a complex healing response. First, hemostasis occurs as blood vessels constrict and platelets form clots to stop bleeding. Then inflammation begins as immune cells rush to the wound site to fight infection and clear debris. Finally, the proliferation phase starts as new cells begin to rebuild the damaged tissue.
During the proliferation phase, specialized cells called fibroblasts migrate to the wound site and begin producing collagen, the main structural protein of skin. In normal skin, collagen fibers are arranged in an organized, parallel pattern. However, in scar tissue formation, fibroblasts produce collagen fibers in a disorganized, random pattern, creating the different texture and appearance characteristic of scars.
The remodeling phase is the final stage of scar formation, lasting from weeks to months. During this time, excess collagen is gradually broken down and the remaining fibers slowly reorganize to become more aligned with the skin surface. The scar transforms from red and raised to flatter and lighter in color. However, the collagen arrangement never fully returns to the organized pattern of normal skin, which is why scars remain permanently visible.
There are four main types of scars that form depending on how the body produces collagen during healing. Normal scars have balanced collagen production and remain flat. Hypertrophic scars result from excess collagen production, creating raised scars that stay within the original wound boundaries. Keloid scars involve excessive collagen overgrowth that extends beyond the original wound area. Atrophic scars form when insufficient collagen is produced, creating depressed or sunken scars below the skin surface.