Reference — Wound Care
Pressure Injury Stages Reference
NPIAP (National Pressure Injury Advisory Panel) staging definitions — Stage 1 through Stage 4, unstageable, and deep tissue pressure injury (DTPI): definitions, tissue involvement, key assessment findings, and nursing interventions.
Educational use only. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.
NPIAP Definitions. The term “pressure injury” replaced “pressure ulcer” in 2016 (NPIAP). Staging applies to pressure injuries specifically — not to other wound types. Once staged, pressure injuries do NOT backstage (a healing Stage 4 is documented as a healing Stage 4, not down-staged to Stage 2).
Quick Overview
| Stage | Tissue Involved | Skin Intact? | Key Marker |
|---|---|---|---|
| Stage 1 | Epidermis | Yes | Non-blanchable erythema only |
| Stage 2 | Epidermis + partial dermis | Partial | Shallow open wound or serum blister |
| Stage 3 | Epidermis + dermis + subcutaneous fat | No | Adipose visible; fascia NOT exposed |
| Stage 4 | Epidermis + dermis + fat + fascia/muscle/bone | No | Bone, muscle, or tendon visible |
| Unstageable | Cannot determine — covered by slough/eschar | No | True stage unknown until debrided |
| DTPI | Deep tissue (muscle/fat) — inside-out injury | No | Dark purple/maroon discoloration; evolves rapidly |
Pressure injuries do NOT backstage — a healing Stage 4 remains documented as Stage 4 throughout healing.
Stage Details
Stage 1
Non-blanchable erythema of intact skin
Intact skin with a localized area of non-blanchable erythema that may appear differently in darkly pigmented skin. Presence of blanchable erythema or changes in sensation, temperature, or firmness may precede visual changes.
Assessment Findings
- Localized redness that does NOT blanch with fingertip pressure (blanching test)
- May appear as skin color change in dark-skinned patients: purple, blue, or darker hue compared to surrounding skin
- Warmth at affected area (vs. surrounding skin)
- Edema or induration of the area compared to surrounding tissue
- Patient may report pain or discomfort at the site
Nursing Interventions
- Relieve pressure immediately — reposition NOW; do NOT leave patient in position causing the injury
- Implement pressure redistribution support surface if not already in use
- Increase repositioning frequency (every 1–2 hours minimum)
- Apply moisture barrier or protective dressing (transparent film or foam) over area
- Document size, location, description; photograph per policy
- Notify provider and wound care specialist
- Nutritional assessment and intervention
NCLEX: Stage 1 is the ONLY stage without skin breakdown. It is reversible with prompt intervention.
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. May also present as an intact or ruptured serum-filled blister. Adipose and deeper tissues are NOT visible. No granulation tissue, slough, or eschar.
Assessment Findings
- Shallow open wound with a red or pink wound bed
- Intact or ruptured serum-filled blister (not containing blood)
- No slough or eschar in wound bed
- Adipose tissue NOT visible
- Most commonly located over bony prominences: sacrum, coccyx, heels, trochanters
Nursing Interventions
- Pressure relief — same as Stage 1 (reposition, support surface)
- Moist wound healing environment — hydrocolloid or foam dressing depending on drainage
- Protect blister if intact (do not open unless infected); cover with non-adherent dressing
- If blister opens: cleanse gently, apply moist wound dressing
- Do NOT use wet-to-dry dressings — this is a clean wound with viable tissue
- Document and photograph; notify provider
- Assess nutritional status
NCLEX: Stage 2 = partial-thickness. Has exposed dermis. No slough, no eschar, no adipose visible.
Stage 3
Full-thickness skin loss
Full-thickness loss of skin in which adipose (fat) tissue is visible in the ulcer and granulation tissue and epibole (rolled wound edges) are often present. Slough and/or eschar may be visible. Depth varies by anatomic location. Fascia, muscle, tendon, ligament, cartilage, and bone are NOT exposed or directly palpable.
Assessment Findings
- Wound cavity with adipose tissue visible in wound bed
- May contain slough (yellow, tan, gray stringy tissue) or eschar
- Granulation tissue may be present if wound is healing
- Rolled wound edges (epibole) may be present
- Undermining or tunneling may be present
- Depth varies: shallow over areas with little adipose (nasal bridge, ear, occiput); deep in areas with significant adipose (trochanter, sacrum)
Nursing Interventions
- Pressure redistribution — advanced support surface
- Wound bed preparation: debridement of slough/eschar if present
- Dressing selection based on drainage and wound characteristics (foam, alginate, hydrocolloid)
- Fill dead space / tunneling with appropriate wound filler
- Wound care specialist consultation
- Nutritional support — protein and vitamin C supplementation per dietitian
- Document size (including undermining/tunneling) and photograph
NCLEX: Stage 3 = full-thickness; fat visible; fascia NOT exposed. Undermining and tunneling common.
Stage 4
Full-thickness skin and tissue loss — bone, tendon, or muscle exposed
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. Epibole, undermining, and/or tunneling often occur.
Assessment Findings
- Bone, muscle, tendon, or ligament visible or directly palpable in wound bed
- Usually contains slough and/or eschar
- Significant depth — deep wound cavity
- Undermining and tunneling frequently present
- High risk for osteomyelitis — probe-to-bone test may be positive
- May develop sepsis, particularly in immunocompromised or critically ill patients
Nursing Interventions
- URGENT — notify provider and wound care specialist immediately
- Rule out osteomyelitis: probe-to-bone; imaging (MRI); bone culture if indicated
- Surgical consultation for debridement or flap closure consideration
- Advanced wound therapies: negative pressure wound therapy (NPWT/VAC), skin substitutes
- IV antibiotics for deep infection
- Nutritional optimization — significant protein requirements for tissue repair
- Sepsis precautions
NCLEX: Stage 4 = BONE, muscle, or tendon visible/palpable. High osteomyelitis risk. Surgical consult usually needed.
Unstageable
Obscured full-thickness skin and tissue loss
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. If slough or eschar were removed, a Stage 3 or Stage 4 pressure injury would be revealed.
Assessment Findings
- Wound bed completely or partially covered by slough (yellow/tan/gray) and/or eschar (dark brown/black)
- True depth cannot be assessed until slough/eschar removed
- Is a Stage 3 or 4 underneath — do NOT document as lower stage
- Exception: dry, stable heel eschar — should NOT be debrided (assess for fluctuance, erythema, drainage, warmth before deciding)
Nursing Interventions
- Debridement required (except dry stable heel eschar) to determine true staging
- Document as Unstageable until debridement reveals depth
- Consult wound care specialist for debridement plan
- Autolytic debridement (hydrogel or hydrocolloid) for gradual approach
- Sharp debridement for urgent cases (provider or wound care specialist)
- Reassess and re-document stage after debridement
NCLEX: Unstageable = covered by slough or eschar — you CANNOT stage it. Must debride first. Heel eschar exception: leave dry stable heel eschar intact.
Deep Tissue Pressure Injury (DTPI)
Persistent non-blanchable deep red/maroon/purple discoloration — intact or non-intact skin
Intact or non-intact skin with localized area of persistent non-blanchable deep red, maroon, or purple discoloration or epidermal separation revealing a dark wound bed or blood-filled blister. Pain and firmness may precede skin color changes. This injury results from intense and/or prolonged pressure and shear forces at the bone-muscle interface.
Assessment Findings
- Dark red, maroon, or purple intact skin OR thin blister over dark wound bed
- Wound may be painful before it becomes visible
- May evolve rapidly into a deep wound despite optimal treatment — indicates extensive tissue death in deeper layers
- Does NOT blanch with pressure
- Typically located over bony prominences where deep tissue is compressed
- May have warmth, pain, firmness, or softness compared to surrounding tissue
Nursing Interventions
- Relieve pressure IMMEDIATELY — deepens extremely rapidly if pressure continues
- Do not apply heat or massage to affected area
- Notify provider and wound care specialist immediately
- Document appearance carefully with photography
- Monitor closely for evolution — may progress to Stage 3 or 4 over hours to days
- Support surface upgrade
- Nutritional optimization
NCLEX: DTPI = inside-out injury. The visible skin may look Stage 1, but deeper tissues are already dead. May worsen dramatically despite good care. Warn families that worsening appearance does not mean worsening nursing care.
Key Rules
- ✦Pressure injuries do NOT backstage — once a Stage 4, always documented as Stage 4 (healing Stage 4, Stage 4 with 80% granulation tissue, etc.)
- ✦Only pressure injuries are staged — venous ulcers, arterial ulcers, and DFUs are NOT staged using the NPIAP system
- ✦Unstageable ≠ Stage 3 or 4 — it means the stage CANNOT be determined yet. Do not guess.
- ✦DTPI: the visible skin may look minor — the underlying tissue damage is often severe. Families and patients must understand worsening appearance may occur despite excellent care.
- ✦Heel eschar exception: dry, stable, intact heel eschar without signs of infection (erythema, warmth, fluctuance, drainage) should NOT be debrided — it provides a protective cover.
- ✦Dark skin: Stage 1 may NOT appear red — look for warmth, firmness, edema, or color change (purple, blue) as early indicators.
Related Resources
Standards & sources
Fact-checked Jun 21, 2026This page is written to align with NPUAP / EPUAP / PPPIA (pressure injury staging) · Wound, Ostomy and Continence Nurses Society (WOCN). It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →