Glossary of Terms


A circumscribed collection of pus that forms in tissue as a result of acute or chronic localized infection. It is associated with tissue destruction and frequently swelling.


Circumscribed removal of the superficial layers of skin.


The presences of viable bacteria in the circulating blood.


Inflammation of cellular or connective tissue. Inflammation may be diminished or absent in immunosuppressed individuals.

Clean Dressing

Dressing that is not sterile but is free of environmental contaminants such as water damage, dust, pest and rodent contaminants, and gross soiling.

Clean Wound

Wound free of purulent drainage, devitalized tissue or dirt.


Containing bacteria, other microorganisms or foreign material. The term usually refers to bacterial contamination and, in this context, is synonymous with colonized. Wounds with bacterial counts of 10 organisms per gram of tissue or less are generally considered contaminated; those with higher counts are generally considered infected.

Culture (Bacterial)

Removal of bacteria from a wound for the purpose of placing them in a growth medium in the laboratory to propagate to the point where they can be identified and tested for sensitivity to various antibiotics. Swab cultures are generally inadequate for this purpose.

Dead Space

A cavity remaining in a wound.


Removal of devitalized tissue and foreign matter from a wound. Various methods may be used for this purpose.

Autolytic Debridement

The use of synthetic dressings to cover a wound and allow eschar to self-digest by the action of enzymes present in wound fluids.

Biologic Debridement

The topical application of sterile maggots to break down devitalized tissue

Enzymatic (Chemical Debridement)

The topical application of proteolytic substances (enzymes) to break down devitalized tissue.

Mechanical Debridement

Removal of foreign material and devitalized or contaminated tissue from a wound by physical forces rather than by chemical (enzymatic) or natural (autolytic) forces. Examples are wet-to-dry dressings, wound irrigation, whirlpool and dextranomers.

Sharp Debridement

Removal of foreign material or devitalized tissue by a sharp instrument such as a scalpel. Laser debridement is also considered a type of sharp debridement.


Separation of the layers of a surgical wound.


Loss of epidermis.


The material applied to a wound for the protection of the wound and absorption of drainage.


Presence of abnormally large amounts of fluid in the interstitial space.


Edges or top layers of epidermis have rolled down to cover lower edges of epidermis, including basement membrane, so that the epithelial cells cannot migrate from wound edges; also described as closed wound edges.


The stage of tissue healing in which the epithelial cells migrate (move) across the surface of a wound.


Redness of the skin

Blanchable Erythema

Reddened area that temporarily turns white or pale when pressure is applied with a fingertip. Blachable erythema over a pressure is applied with a fingertip. Blanchable erythema over a pressure site is usually due to a normal reactive hyperemic response.

Nonblanchable Erythema

Redness that persists when fingertip pressure is applied. Nonblanchable erythema over a pressure site is a symptom of a State 1 pressure ulcer.


Thick, leathery, necrotic, devitalized tissue.


Linear scratches on the skin.


Any fluid that has been extruded from a tissue or its capillaries, more specifically because of injury or inflammation. It is characteristically high in protein and white blood cells.


A sheet or band of fibrous tissue that lies deep below the skin or encloses muscles and various organs of the body.


Mechanical force exerted when ski is dragged across a coarse surface such as bed linens.

Full-Thickness Tissue Loss

Loss of tissue below the dermis level, involving subcutaneous and possibly other tissue layers, to include loss of fascia, tendons, muscles, bone or other underlying structures, full-thickness wounds heal by formation of granulation tissue, contraction, and epitheliazation.

Granulation Tissue

The pink/red, moist tissue that contains new blood vessels, collagen, fibroblasts and inflammatory cells which fills an open, previously deep wound when it starts to heal.


A dynamic process in which anatomical and functional integrity is restored. This process may be monitored and measured. For wounds of the skin, it involves repair of the dermis (granulation tissue formulation) and epidermis (epitheliazation). Healed wounds represent a spectrum of repair; they can be ideally healed (tissue regeneration), minimally healed (temporary return of anatomical continuity) or acceptably healed (sustained functional and anatomical result). The acceptably healed wound is the ultimate outcome of wound healing but not necessarily the appropriate outcome for all patients.

Primary Intention Healing

Closure and healing of a sutured wound.

Secondary Intention Healing

Closure and healing of a wound by the formation of granulation tissue and epithelialization.

Tertiary Healing

Wound left open above the fascia layer which is surgically closed at a later time.


Abnormal firmness of tissue with a definite margin.


Overgrowth of microorganisms capable of tissue destruction and invasion, accompanied by local and/or systemic symptoms.


Cleansing by a stream of fluid, preferably saline.


Deficiency of blood supply to a tissue, often leading to tissue necrosis.


To soften by wetting or soaking. In (a healing) context, it refers to degenerative changes and disintegration of skin when it has been kept too moist.


In the context of this document, moisture refers to skin moisture that may increase the risk of pressure ulcer development and impair healing of existing ulcers. Primary sources of skin moisture include perspiration, urine, feces, drainage from wounds of fistulas.

Necrotic Tissue

Tissue that has died and has, therefore, lost its usual physical properties and biological activity. Also called “devitalized tissue.”


Inflammation of the bone marrow and adjacent bone, often due to infection.

Pressure (Interface)

Force per unit area that acts perpendicularly between the body and the support surface. This parameter is affected by the stiffness of the support surface, the composition of the body tissue and the geometry of the body being supported.

Pressure Reduction

Reduction of interface pressure, not necessarily below the level required to close capillaries (i.e. capillary-closing pressure).

Pressure Relief

Reduction of interface pressure below capillary-closing pressure.