Scars are areas of fibrous tissue (
fibrosis) that replace normal
skin after injury. A scar results from the biological process of
wound repair in the skin and other
tissues of the body. Thus, scarring is a natural part of the
healing process. With the exception of very minor
lesions, every wound (e.g., after
accident,
disease, or
surgery) results in some degree of scarring. An exception to this are animals with complete
regeneration, which regrow tissue without scar formation.