A scar is a mark that is left on the skin after a wound or an injury to the surface of the skin has healed.
Scars are very common – most people have at least one on their body. They are a natural part of the healing process.
Scars can occur inside and outside the body. For example, they can occur on the internal organs where a cut has been made during surgery, and can develop after certain skin conditions, such as acne and chicken pox.
How do scars form?
When the skin is wounded and there is a break in the body’s tissues, the body produces more of a protein called collagen, as part of the healing process. Collagen builds up where the tissue has been damaged, helping to heal and strengthen the wound.
For a period of about three months or longer, new collagen continues to form and blood supply increases, causing the scar to become raised, lumpy and red. Some collagen then breaks down at the site of the wound, the blood supply reduces and the scar gradually becomes smoother, softer and paler.
Although scars are permanent, they can fade over a period of up to two years. It is unlikely they will fade any more after this time.
Skin wounds can be caused by many things, including:
- accidental injuries
- burns and scalds
- intentional harm
Read more about the causes of scars.
Where do scars form?
Scarring is unpredictable and varies from person to person. Certain areas of the body are more at risk of scarring, such as the chest, back, ear lobe and the shoulder.
Scars that form on the knees and shoulders can appear stretched or widened as a result of the healing process occurring over movable joints.
Types of scars
The different types of scars include:
- Flat, pale scars – these are the most common type of scar and are due to the body's natural healing process. Initially, they may be red or dark and raised after the wound has healed, but will become paler and flatter naturally over time. This can take up to two years.
- Hypertrophic scars – red, raised scars that form along a wound and can remain this way for a number of years.
- Keloid scars – these are caused by an excess of scar tissue produced at the site of the wound, where the scar grows beyond the boundaries of the original wound, even after it has healed.
- Pitted (atrophic or "ice-pick") scars – these have a sunken appearance.
- Contracture scars – these are caused by the skin shrinking and tightening, usually after a burn, which can restrict movement.
Read more about the types of scars.
Depending on the type and age of a scar, a variety of different treatments may help make them less visible and improve their appearance.
Scars are unlikely to disappear completely, although most will gradually fade over time.
If scarring is unsightly, uncomfortable or restrictive, treatment options may include:
- silicone gel sheets
- pressure dressings
- corticosteroid injections
- cosmetic camouflage (make-up)
It is often the case that a combination of treatments can be used.
Read more about treating scars.
Emotional effects of scarring
Scarring, particularly when it is on the face, can be very distressing, especially if you feel you are being stared at. If you avoid meeting people as a result of your appearance, you may become socially isolated. This can lead to feelings of depression.
If you feel that your scars are making you depressed or affecting your daily activities, make sure you visit your GP.
Preventing or improving scars
It isn't possible to prevent scars from forming, but there are things you can do to help your scar be less visible and heal better, such as immediately cleaning dirt, objects and dead tissue from wounds.
Other ways to improve scarring include:
- not scratching or picking at scabs and spots
- covering wounds with a waterproof ointment (such as Vaseline)
- using silicone gels or sheets to reduce redness and encourage healing