Scar Formation
How the body repairs wounds and leaves scar tissue
Quick Facts
- Type: Skin and tissue healing process
- What it is: The body's natural wound repair
- Affected by: Wound depth, location, and skin type
- Common types: Flat, raised, keloid, or sunken scars
Overview
Scar formation is the body's natural way of repairing injured skin or tissue. When the skin is cut, burned, or otherwise damaged below its surface, the body produces a protein called collagen to close the wound. The new tissue that forms is a scar, which is slightly different in texture, color, and strength from the surrounding skin.
Scarring is a normal and necessary part of healing. Most scars fade and flatten over time, but some become raised, sunken, or discolored. How a scar turns out depends on the wound, the part of the body, and individual factors such as skin type and age.
Symptoms
A forming scar can have several appearances and sensations:
- A flat or slightly raised mark that may be pink, red, or darker than nearby skin
- A firmer or smoother texture than the surrounding skin
- Itching or tightness as the wound heals
- Gradual fading and softening over months
- In some cases, raised scars (hypertrophic or keloid) or sunken, pitted scars
Causes
Scars form wherever the skin or deeper tissue is injured beyond its surface layer. Common triggers include:
- Cuts, scrapes, and puncture wounds
- Surgery and medical procedures
- Burns
- Acne, chickenpox, and other skin conditions
- Infections and inflammation in the skin
Risk Factors
- Deep, large, or high-tension wounds
- Wounds that become infected or heal slowly
- A personal or family tendency to form raised or keloid scars
- Wounds on areas such as the chest, shoulders, and back
- Sun exposure on a healing wound, which can darken the scar
Diagnosis
A scar is usually identified simply by its appearance and history. A doctor or dermatologist may classify the scar, for example as a flat, raised (hypertrophic), keloid, sunken (atrophic), or contracture scar, to guide care. Rarely, a biopsy is done if a growth on the skin does not look like a typical scar.
Treatment
Many scars need no treatment and fade on their own, but options exist to improve their appearance or symptoms:
- Good wound care: Keeping a healing wound clean and moist and protected from the sun supports a better scar.
- Silicone sheets or gel: Can soften and flatten scars over time.
- Corticosteroid injections: For raised or keloid scars.
- Laser therapy: To reduce redness and improve texture.
- Other procedures: Such as resurfacing, surgical revision, or treatments for sunken acne scars.
Results vary, and scars can be improved but rarely removed completely.
Prevention
- Clean wounds promptly and keep them covered and moist while healing
- Avoid picking at scabs and reopening wounds
- Protect healing skin from the sun to prevent darkening
- Use silicone gel or sheets on new wounds if you are prone to noticeable scars
- Seek care early for wounds that are deep, gaping, or slow to heal
When to See a Doctor
See a doctor if a scar is growing, becoming painful, itchy, or thick, restricting movement, or bothering you cosmetically. Also seek care for a wound that is deep, will not stop bleeding, shows signs of infection such as spreading redness, warmth, or pus, or is slow to heal, since proper wound care can reduce scarring.
Frequently Asked Questions
Why do scars form?
Scars form because the body repairs deeper skin injuries by producing collagen to close the wound. This new tissue is stronger and faster to make than perfectly matched skin, so it differs in texture and color, leaving a scar. Scarring is a normal part of healing.
Can scars be removed completely?
Most scars can be improved but not erased entirely. Treatments such as silicone gel, laser therapy, injections, and surgery can make scars flatter, softer, or less noticeable, but some mark usually remains. Good early wound care gives the best chance of a less visible scar.
How can I reduce scarring from a wound?
Keep the wound clean, covered, and moist while it heals, avoid picking at scabs, and protect the area from the sun. Using silicone gel or sheets can help, especially if you tend to form noticeable scars. Treating deep or slow-healing wounds early also helps.
When should I see a doctor about a scar?
See a doctor if a scar grows beyond the wound, becomes thick, painful, or itchy, limits movement, or bothers you cosmetically. Also seek care if the original wound shows signs of infection or is slow to heal, since this affects how the scar forms.
References
- American Academy of Dermatology. Scars: Overview and treatment.
- MedlinePlus, U.S. National Library of Medicine. Scars.
- Mayo Clinic. Wound care and scarring.