ConditionSkin, hair & nails
Scarring
Scarring is the skin's natural way of repairing a wound. When the deeper layer of skin (the dermis) is damaged by an injury, surgery, burn or acne, the body lays down collagen fibers to close the gap, forming a scar. Most scars are red or pink at first, then flatten and fade over 12 to 18 months. Some become raised (hypertrophic or keloid), sunken (atrophic, as with acne) or tight (contractures). Good wound care reduces scarring, and many treatments can improve a scar's appearance.
Also called: Scars, scar tissue, cicatrix, hypertrophic scar, keloid
At a glance
- What it is
- Fibrous tissue that replaces normal skin after damage to the dermis.
- Main types
- Flat (normal), hypertrophic, keloid, atrophic (sunken), contracture.
- Timeline
- Red and raised for weeks to months; matures and fades over 12 to 18 months.
- Risk factors
- Deep wounds, infection, tension on the wound, burns, darker skin (keloids), genetics.
- Prevention
- Clean, moist wound healing; avoid picking; sun protection; silicone after closure.
- Treatments
- Silicone, pressure, steroid injections, lasers, microneedling, fillers, surgical revision.
When to get help
See a doctor within a day or two
- A healing wound that becomes increasingly red, hot, swollen, painful or drains pus, or you have fever
- A burn scar or scar across a joint that is tightening and limiting movement
Book a routine appointment
- A scar that keeps growing beyond the original wound edges (possible keloid)
- A raised, itchy or painful scar
- A scar or long-standing wound that breaks down, bleeds or changes shape (rarely a skin cancer)
- Scars that affect confidence or function
Usually safe to manage at home
- A new, pink, slightly raised scar from a healed cut or surgery that is slowly flattening
How scars form
Wound healing has three overlapping phases:
- Inflammation (days 1 to 5): bleeding stops and immune cells clean the wound.
- Proliferation (days 4 to 21): new tissue and blood vessels form; collagen is laid down; the wound contracts.
- Remodeling (3 weeks to 1 to 2 years): collagen is reorganized and strengthened; the scar becomes flatter, paler and softer.
Scar tissue is never identical to normal skin. It has no hair follicles or sweat glands and reaches only about 80% of the original strength.
Types of scars
| Type | Appearance | Notes |
|---|---|---|
| Flat (mature) scar | Thin, pale line | The normal outcome |
| Hypertrophic scar | Raised, red, firm, within the wound borders | Common after burns and wounds under tension; often improves over 1 to 2 years |
| Keloid | Raised, shiny, rubbery; grows beyond the original wound | More common on chest, shoulders, earlobes; more frequent in people with darker skin; often itchy; tends to recur |
| Atrophic scar | Sunken or pitted | Acne, chickenpox; types include icepick, boxcar and rolling scars |
| Contracture | Tight, thickened skin pulling edges together | After burns; can limit movement across joints |
| Stretch marks (striae) | Linear streaks | Dermal stretching in pregnancy, growth spurts, weight changes, steroids |
Risk factors for worse scarring
- deep or large wounds, burns (burn) and wounds that take more than 2 to 3 weeks to heal
- wound infection
- tension across the wound (chest, shoulders, joints)
- picking scabs, or squeezing acne
- genetics and family history of keloids
- darker skin tones, for keloids and post-inflammatory hyperpigmentation
- age: young people form thicker scars; older skin often scars less visibly
- smoking and poor nutrition
How to reduce scarring
While the wound heals
- Clean gently with soap and water.
- Keep it moist with petroleum jelly and a covering; moist wounds heal faster and scar less than dry, scabbed wounds.
- Do not pick scabs.
- Close deep or gaping wounds promptly with stitches, staples, glue or strips, ideally within hours.
- Watch for infection.
After the wound closes
- Silicone gel or sheets: the first-line treatment to prevent and flatten raised scars. Use daily for at least 2 to 3 months.
- Sun protection: SPF 30 or higher or clothing for 12 to 18 months, as sun darkens new scars.
- Massage: gentle massage with moisturizer once healed may help soften scars.
- Pressure garments: for burn scars, worn many hours a day for months.
Treatments for existing scars
- Steroid injections: flatten and soften hypertrophic scars and keloids; often repeated every 4 to 6 weeks.
- Lasers: pulsed dye laser reduces redness; fractional lasers improve texture and atrophic scars.
- Microneedling and chemical peels: improve acne scars.
- Fillers: temporarily raise sunken scars.
- Subcision: releases tethered acne scars.
- Cryotherapy: freezing for keloids.
- Surgical scar revision: removes or reorients a scar, often combined with other treatments; keloids need post-surgery steroid injections or radiation to reduce recurrence.
- Contracture release surgery and grafts for burn contractures, with physical therapy.
Results are gradual. Most treatments improve rather than erase scars.
Frequently asked questions
How long does it take for a scar to fade?
Most scars are red or pink and slightly raised for the first few months, then gradually flatten and fade over 12 to 18 months. Scars on the face often heal better than those on the chest, back or legs. Some changes continue for up to 2 years.
What is the difference between a keloid and a hypertrophic scar?
Both are raised scars. A hypertrophic scar stays within the borders of the original wound and often improves with time. A keloid grows beyond the wound edges, rarely regresses on its own, and frequently returns after removal without additional treatment.
What is the best way to prevent scarring?
Keep the wound clean and moist while it heals, avoid picking scabs, get deep cuts closed promptly, and protect the area from the sun. Once closed, silicone gel or sheets for a few months help prevent raised scars.
Can scars be removed completely?
No treatment fully restores normal skin, but many can make scars much less noticeable. Options include silicone, steroid injections, lasers, microneedling, fillers and surgical revision. A dermatologist or plastic surgeon can recommend the best approach.
Sources
This guide was written from current patient and clinical guidance, including:
- American Academy of Dermatology: Scars, diagnosis and treatment
- American Academy of Dermatology: Keloids
- NHS: Scars
- MedlinePlus: Scars
- International Advisory Panel on Scar Management: Updated scar management practical guidelines