| Stage 1 | Non-blanchable erythema of intact skin• Intact skin with a localized area of non-blanchable erythema. which may appear differently in darkly pigmented skin.• Presence of blanchable erythema or changes in sensation, temperature, or firmness may precede visual changes. |
| Stage 2 | Partial-thickness skin loss with exposed dermis• Partial-thickness loss of skin with exposed dermis.• The wound bed is viable, pink or red, moist, and may also present as an intact or ruptured serum-filled blister.• Adipose (fat) is not visible and deeper tissues are not visible. Granulation tissue, slough and eschar are not present. |
| Stage 3 | Full-thickness skin loss• 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.• Slough and/or eschar may be visible. The depth of tissue damage varies by anatomical location; areas of significant adiposity can develop deep wounds. |
| Stage 4 | Full-thickness skin and tissue loss• Full-thickness skin and tissue loss with exposed or directly palpable fascia, muscle, tendon, ligament, cartilage or bone in the ulcer. Slough and/or eschar may be visible. |
| Unstageable Pressure Injury Obscured full-thickness skin and tissue loss |
| Deep Tissue Pressure InjuryPersistent non-blanchable deep red, maroon or purple discoloration |