Scar tissue is repair tissue. When an injury goes deeper than the top layer of skin, the body does not rebuild what was there — it bridges the gap with collagen, quickly, because closing the wound matters more than matching the original. The result is functional but different: fewer hair follicles, fewer oil and sweat glands, less pigment, less stretch, and a different texture from the skin around it.
The three phases, briefly
Injury. The dermis is damaged and the body starts its healing response.
Repair. New collagen fibres are laid down to close the gap. In an uncomplicated wound, collagen production and breakdown reach a rough balance within the first couple of months.
Maturation. Over the following months the scar gets stronger, often thickening first, then gradually flattening and fading as the tissue reorganises. This is the long tail — and it is the phase topical care is trying to influence.
When production and breakdown do not balance, you get an abnormal scar.
Why scars turn out differently
Tension and location. A wound across an area that moves or stretches — a shoulder, a knee, the chest — is pulled apart with every movement, and the body answers by laying down more collagen. Still areas heal quieter.
Depth. Deeper injuries need more repair tissue, and produce more visible scars.
Genetics and skin tone. Keloids run in families and are reported more often in people with darker skin. This is not something you influence; it is something to plan around.
Age. Younger skin tends to scar more vigorously than older skin.
Health. Diabetes, some skin conditions and a compromised immune system all slow healing, and slow healing tends to scar more.
Infection and wound care. Infection prolongs inflammation and disrupts normal healing. Good wound care is one of the few levers anyone has.
Timing of scar care. Starting once the wound has closed, rather than months later, works with the remodelling window rather than after it.
The four kinds you will hear about
- Hypertrophic — raised, often red and itchy, but staying inside the boundaries of the original wound. Frequently improves on its own over a year or more.
- Keloid — grows beyond the original wound edges, can appear up to a year after the injury, can be painful and can keep growing. More common on the chest, shoulders, back and earlobes.
- Atrophic — a depression rather than a bump, from insufficient connective tissue. Common after acne or chickenpox.
- Contracture — usually after burns; tight, inflexible, and able to restrict movement when it crosses a joint.
The difference matters, because they do not respond to the same things. A raised scar and a depressed scar are opposite problems. Our conditions section covers each in turn.
What is still in your hands
You cannot change your genetics, where the incision had to be, or how deep the injury went. What is left: keeping the healing wound clean and getting infection treated, protecting a new scar from sun, keeping the tissue moisturised, and starting consistent topical care as soon as the skin has closed.