Chart — Fundamentals
Pressure Injury Staging Comparison
Side-by-side NPIAP staging comparison — all six pressure injury categories with skin findings, tissue involvement, and nursing considerations for NCLEX and clinical practice.
Educational use only. Pressure injury staging requires in-person clinical assessment. Wounds are never back-staged. This chart is for nursing education and NCLEX preparation. 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.
NCLEX Tip: Stage 3 = subcutaneous fat visible, no bone/tendon/muscle. Stage 4 = bone, tendon, or muscle exposed. Wounds never back-stage as they heal. Stable heel eschar is NOT debrided.
All Stages — Comparison
Stage 1
Non-Blanchable Erythema
Intact skin with non-blanchable localized redness; may appear violet or maroon in dark skin tones; area may feel warmer, cooler, firmer, or softer than surrounding skin
Skin intact — epidermis only affected; no open wound; microvascular changes indicate impaired perfusion
Act immediately — this is the warning sign. Increase repositioning frequency. Apply protective foam dressing to affected area. Assess Braden score and implement full prevention protocol.
NCLEX: Blanchability test: press 3 seconds — non-blanchable = Stage 1. This is the earliest visible stage.
Stage 2
Partial Thickness Skin Loss
Shallow open ulcer with pink or red, moist wound bed; OR intact or ruptured serum-filled blister; no slough or bruising (bruising suggests DTI)
Partial thickness dermis loss — epidermis and upper dermis destroyed; subcutaneous fat not visible; wound bed is viable (pink/red)
Moisture-retentive dressing (hydrocolloid, thin foam) to maintain moist wound environment. Relieve pressure. Manage moisture. Pain management — Stage 2 is often very painful due to exposed nerve endings.
NCLEX: No slough or bruising in true Stage 2. Blister: do not rupture unless at risk of infection. Very painful — assess and manage pain.
Stage 3
Full Thickness Skin Loss
Full thickness tissue loss; wound crater; subcutaneous fat may be visible; slough or eschar may be present but does not obscure depth; undermining and tunneling may be present
Epidermis, dermis, and subcutaneous fat involved; bone, tendon, and muscle are NOT visible or directly palpable
Assess and document wound dimensions (L×W×D), undermining, and tunneling. Moist wound healing approach. Consult wound care specialist. Nutritional support — protein and calories critical. Debridement per order if necrotic tissue present.
NCLEX: Stage 3: subcutaneous fat visible but no bone/tendon/muscle. Stage 4: bone/tendon/muscle exposed. This distinction is high-yield for NCLEX.
Stage 4
Full Thickness Tissue Loss
Full thickness tissue loss with exposed or directly palpable bone, tendon, or muscle; slough or eschar may be present on portions; undermining and tunneling common
All tissue layers destroyed — epidermis, dermis, subcutaneous fat, fascia; bone, tendon, or muscle directly exposed or palpable
Monitor for osteomyelitis (probe-to-bone test positive = presumed osteomyelitis). Multidisciplinary team required. Assess for systemic infection. Negative pressure wound therapy (NPWT) may be ordered. Surgical consult may be necessary.
NCLEX: Stage 4 carries significant osteomyelitis risk. If a sterile probe contacts bone during wound assessment, osteomyelitis is presumed until proven otherwise.
Unstageable
Obscured Full Thickness
Full thickness loss with wound bed obscured by slough (yellow, tan, gray, green) or eschar (tan, brown, black); true wound depth cannot be determined
Full thickness — actual depth hidden; once debrided, typically reveals Stage 3 or 4 wound. Exception: stable dry adherent heel eschar is not debrided
Document as unstageable. Assess for infection signs under eschar (odor, fluctuance, periwound changes). Debridement per provider order — do not debride without an order. Heel eschar exception: do not debride stable, dry, adherent heel eschar — it is a natural protective cover.
NCLEX: Unstageable ≠ unknown stage — it means the wound bed is obscured. Stable heel eschar is NOT debrided. This is a commonly tested NCLEX exception.
Deep Tissue PI
Persistent Deep Red / Purple Discoloration
Non-blanchable deep red, maroon, or purple discoloration of intact or nearly intact skin; OR blood-filled blister; pain and temperature changes often precede visible changes
Damage at the bone-muscle interface from intense and/or prolonged pressure and shear; overlying skin may appear intact while deeper tissue is already necrotic
Immediate pressure relief. Monitor closely at every shift — may evolve rapidly to Stage 3 or 4 within hours or days despite optimal care. Notify provider. Document evolution carefully. Do not massage area over bony prominences.
NCLEX: DTI can evolve rapidly — it is not safe or stable. Intense pressure over bony prominence is the mechanism. Dark discoloration with intact skin = DTI until proven otherwise.
Quick Reference Summary
| Stage | Skin Intact? | Deepest Tissue Visible | Key Feature |
|---|---|---|---|
| Stage 1 | Yes | Epidermis (intact) | Non-blanchable erythema |
| Stage 2 | No (open wound or blister) | Dermis (partial) | Shallow ulcer or blister; no slough |
| Stage 3 | No | Subcutaneous fat | Full thickness; fat visible; no bone/tendon |
| Stage 4 | No | Bone, tendon, or muscle | Bone/tendon/muscle exposed; osteomyelitis risk |
| Unstageable | No | Cannot determine (obscured) | Slough/eschar obscures wound bed |
| Deep Tissue PI | Yes (or nearly) | Deep tissue (not visible externally) | Purple/maroon discoloration; may evolve rapidly |
Related Resources
Standards & sources
Fact-checked Jun 21, 2026This page is written to align with American Nurses Association (ANA) Standards of Practice · The Joint Commission. 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 →
