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 scar on their body. They are a natural part of the healing process and can occur inside and outside the body.
Visible scars sometimes form after the skin has been broken. Scars can also occur on the internal organs – for example, where a cut has been made during surgery. Scars can also develop as a result of certain skin conditions, such as acne.
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. Collagen builds up where the tissue is broken, helping to heal and close the wound.
For a period of months and years, new collagen continues to form and break down at the site of the wound. The scar gradually becomes smoother and softer.
Scars on the skin can take up to two years to fade. After this time it is unlikely that they will fade any more.
Read more about the causes of scars.
Stretch marks are types of scars that appear on the surface of the skin as a result of sudden growth, such as pregnancy or weight gain. See the Health A-Z topic about Stretch marks for more information.
Abnormal scars
Sometimes, abnormal scars develop. There are two types of abnormal scars:
- A hypertrophic scar is a red, raised scar that can form when there's excessive wound healing, for some reason.
- A keloid scar is an overgrowth of tissue that occurs when too much collagen is produced at the site of the wound and the scar keeps growing, even after the wound has healed.
Where do scars form?
Certain areas of the body are more likely to produce worse scars than others. Poor scars are more likely to form in the middle of the chest, the earlobe and the tip of the shoulder. These areas are also more prone to abnormal scars.
Scars that form on the knees and shoulders are often more visible because they need to move and stretch during the healing process. Also, different skin types form different types of scars.
Emotional effects
Scarring, particularly when it is on the face, can be very distressing. For some people, scarring can affect them a great deal. It may feel as if you are being stared at, and if you avoid meeting people as a result of your appearance, it can make you feel isolated. These feelings can lead to depression. If you if you feel that your scars are making you depressed or affecting your daily activities, visit your GP.
Outlook
A variety of different treatments can make scars less visible and improve their appearance. But the options available to you may depend on the type of scar that you have.
Be aware that scars never disappear completely, although most will gradually fade over a long period of time.
Over time, normal scars and hypertrophic scars will fade and become much paler. Keloid scars and more severe hypertrophic scars can be treated using:
- corticosteroid injections
- silicone gel sheets
- surgery
- pressure dressings
See Scars - treatment for more information.
