The human body can sustain a variety of wounds such as burns, cuts, and knocks or bangs. Well, all of these aggressions initiate an orderly sequence of steps that are involved in the healing response, in which the normal functional tissue (skin) is replaced by connective tissue (scar). The healing response is also characterized by the migration of specialized cells into the wound site.

The restoration of anatomical continuity and function is the result of the complex and dynamic process of healing. Following an injury, your body can respond in 4 different ways:

1.Regeneration (exact replacement)

The skin regeneration process occurs when there is loss of structure and function. The beauty of our organism is that it has the sophisticated capacity to restore that tissue by replacing exactly what was there before the injury. Smaller forms of life, such as the salamander and crab, can regenerate tissue in this way. Throughout the past million years, we have lost this capacity and can only replace a limited amount of damaged tissues by the process of regeneration.

2. Normal repair (reestablished equilibrium)

Normal repair is the response where there is a re-established equilibrium between scar formation and scar remodeling. Most humans experience this type of response following an injury. The abnormal response to tissue injury stand in sharp contrast to the normal repair response.

3. Excessive healing (fibrosis and contractures)

In excessive healing there is an exaggerated deposition of connective tissue; this produces an altered tissue and, thus, loss of function. Fibrosis, structures, adhesions and contractures are examples of exaggerated healing. Keloids and hypertrophic scars in the skin are examples of fibrosis. Contraction is normal during the process of healing but if exaggerated, it becomes pathologic and is known as a contracture.

4. Deficient healing (chronic ulcers)

Deficient healing is the opposite of fibrosis; it exists when there is an abnormally low deposition of connective tissue matrix and the tissue is thinned to the point where it can fall apart. Persistent non-healing ulcers are examples of deficient healing.

The Scar Healing Process

Just as an injury occurs, several different cells are sent to the damaged site, and the complex healing process begins.

The normal healing cascade commences with an orderly process of hemostasis and fibrin deposition, which leads to an inflammatory cell cascade, characterized by neutrophils, macrophages and lymphocytes within the tissue. This is followed by migration and proliferation of fibroblasts and collagen deposition, and finally remodeling by collagen cross-linking and scar maturation. Despite this orderly sequence of steps leading to normal wound healing, pathologic responses leading to fibrosis or chronic ulcers may occur if any step of the healing cascade is altered.