The skin is a dynamic organ capable of regenerating itself after injuries. However, some injuries cause the skin to heal with scarring. Scarring injuries can cause depressions in the skin surface such as those formed as the result of acne, surgery, stretch marks, burns, injuries or infections. Other times they can form a raised scar or keloid as a result of too much scar tissue in the wound. Although a scar can never completely disappear, certain laser treatments can greatly improve the appearance of the scar.