There are many different types of scars, some differing in their composition and some in how they were caused. Here are a few of the most common types of scars:

Hypertrophic scars. These are scars which develop when the body produces too much collagen. This causes the scar to end up raised above the skin surrounding it, usually in the form of a red raised lump. They occur after around 4 to 8 weeks after a wound closing of becoming infected.

Keloid scars. These scars are more serious, because they can sometimes grow into tumorous (although usually benign) neoplasms. Keloid scars are most common in people with dark skin, and they usually appear as a mass of collagen on the chest or shoulders. They are a cosmetic problem for many people, but can be treated with laser treatment.

Atrophic scars. These are scars which have a pitted appearance, looking like sunken recesses in the skin. They are caused when fat, muscle or other structures supporting the skin are lost.

Acne scars. These are a form of atrophic scar, caused by severe acne or chickenpox.

Stretch marks. These are considered to be a form of scarring caused by the skin stretching during pregnancy, adolescent growth spurts or other rapid weight loss or gain. Stretch marks can be treated effectively with laser stretch mark removal treatment.