Pressure-induced injury by stage

Pressure-induced injury staging​^[1].
(A) Stage 1 – Skin intact but with nonblanchable redness.
(B) Stage 2 – Partial-thickness loss of skin with exposed dermis.
(C) Stage 3 – Full-thickness loss of skin, in which adipose (fat) is visible in the ulcer and granulation tissue and epibole (rolled wound edges) are often present.
(D) Stage 4 – Full-thickness skin and tissue loss with exposed or directly palpable fascia, muscle, tendon, ligament, cartilage, or bone in the ulcer.
Not shown:
Unstageable pressure injury – Full-thickness skin and tissue loss in which the extent of tissue damage within the ulcer cannot be confirmed because it is obscured by slough or eschar.
Deep tissue pressure injury – Deep tissue pressure injury should be suspected whenever there is a localized area of skin (intact or non-intact) with persistent nonblanchable deep red, maroon, or purple discoloration or epidermal separation revealing a dark wound bed or blood-filled blister.