Scars on the skin may appear when a cut or other injury is in the process of healing. The different types of scars vary in appearance.

Flat, pale scars

The most common type of scar is the flat, pale scar that forms as a result of 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 as the injury heals.

This process can take up to two years, and there will always be some visible evidence of the original wound.  

If the skin at the edges of the wound has come together neatly, the scar will usually heal as a thin, pale line. In wider wounds, where more surface skin is missing and more scar tissue is needed to bridge the gap between the edges of damaged skin (such as a bad graze on the knee), the scar may be less neat and may take longer to heal.

These scars are not usually painful, although they may be itchy for a few months. They can also be quite dark in colour and unsightly.

If you have a darker skin type, scar tissue may fade to leave a brown or white mark. These are often permanent, but can sometimes improve over time. If your skin is tanned, the scar may appear more obvious, as scar tissue does not tan and remains pale.

Other scars

Keloid scars

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.

Keloid scars often have the following characteristics:

• they are often raised above the skin 
• they can feel itchy
• they can feel painful
• they can appear much larger than the original wound
• they can cause a burning sensation and feel tender to touch
• they can restrict movement if they are tight and near a joint
• they are raised above the skin
• they are hairless and appears shiny
• they feel hard and have a "rubbery" texture, although some keloids can form soft lumps (such as on the ear lobe after piercings)
• a newly-formed keloid scar is red or purple, becoming paler with time

The areas of the body where keloid scars are more likely to form include:

• the area around the breastbone (sternum)
• the upper arms and shoulders (deltoids)
• the upper back 
• on the ear lobes 

Hypertrophic scars

Like keloid scars, hypertrophic scars are the result of an imbalance in the production of collagen in a healing wound.

Unlike keloid scars, they do not extend beyond the boundary of the original wound, but may continue to thicken for up to six months. 

A hypertrophic scar is a red, raised scar that forms along a wound and can have the following characteristics for around two to five years:

• it can restrict movement because scar tissue is not as flexible as the original skin
• it heals within the size of the original wound
• the healing tissue is thicker than usual
• it is red and raised initially, becoming flatter and paler with time

Hypertrophic scars can have this appearance for many years.

Pitted or sunken scars (atrophic or "ice-pick" scars)

Some scars caused by skin conditions such as acne and chickenpox can have a sunken or pitted appearance.

They can also be the result of an injury, which may have included the loss of underlying fat.

Scar contractures

Scar contractures are commonly caused by burns. These occur when the skin “shrinks”, leading to tightness and a restriction in movement.