Pressure Injury Staging Guide: Assessment, Documentation, and Treatment by Stage

Pressure injuries account for approximately 2.5 million cases per year in the United States, and incorrect staging is a leading cause of inadequate treatment plans, billing denials, and preventable clinical deterioration. Staging drives everything downstream — the treatment protocol, the support surface order, the CPT code billed, and the LCD documentation that keeps the claim compliant. Get the stage wrong and the entire care plan follows the wrong track.

This guide covers the Braden Scale risk assessment, each NPUAP/EPUAP stage with its clinical criteria, the documentation requirements that satisfy payer scrutiny, and the treatment protocols appropriate to each stage of tissue damage.

Braden Scale Risk Assessment

The Braden Scale is the standard risk assessment tool for pressure injury prevention. It evaluates six subscales, each scored independently, with total scores ranging from 6 (highest risk) to 23 (lowest risk). Every patient admitted to a facility — and every home health patient on service — should have a Braden assessment completed on admission and reassessed at regular intervals.

The Six Subscales

Sensory Perception (1-4): The patient's ability to respond meaningfully to pressure-related discomfort. A score of 1 indicates completely limited perception (unresponsive to painful stimuli). A score of 4 indicates no impairment.

Moisture (1-4): The degree to which skin is exposed to moisture from perspiration, urine, or wound drainage. A score of 1 means the skin is almost constantly moist. A score of 4 means the skin is rarely moist.

Activity (1-4): The patient's degree of physical activity. A score of 1 means the patient is bedfast. A score of 4 means the patient walks frequently outside the room.

Mobility (1-4): The patient's ability to change and control body position. A score of 1 means the patient is completely immobile without assistance. A score of 4 means the patient makes frequent, independent position changes.

Nutrition (1-4): The patient's usual food intake pattern. A score of 1 means the patient never eats a complete meal, rarely takes more than one-third of any food offered, and protein intake is inadequate. A score of 4 means the patient eats most of every meal with adequate protein.

Friction and Shear (1-3): The patient's exposure to friction against surfaces and shear forces during repositioning. A score of 1 indicates a significant problem — the patient requires moderate to maximum assistance with movement and slides against sheets frequently. A score of 3 indicates no apparent problem.

Score Interpretation

15-18: Mild risk. Implement standard prevention protocols — regular skin assessment, moisture management, adequate nutrition screening.
13-14: Moderate risk. Add pressure redistribution surfaces, structured repositioning schedules, and nutritional supplementation if intake is borderline.
10-12: High risk. Group 1 support surfaces, strict every-two-hour repositioning protocol, dietary consultation for protein optimization, and daily skin assessment at all bony prominences.
9 or below: Very high risk. Group 2 support surfaces, aggressive nutritional intervention, consider specialty bed, and evaluate every contributing factor — moisture, friction, immobility, sensory deficit — individually.

Document the Braden score, the individual subscale scores, and the prevention interventions implemented in response to the assessed risk level. Payers and auditors look for the connection between the score and the care plan — a Braden score of 10 with no documented prevention interventions is a red flag for both clinical quality and compliance.

Stage 1: Non-Blanchable Erythema of Intact Skin

Clinical Criteria

Stage 1 is intact skin with a localized area of non-blanchable erythema, which may appear differently in darkly pigmented skin. The area may be painful, firm, soft, warmer, or cooler compared to adjacent tissue. The key clinical test: press a finger firmly on the reddened area and release. If the skin does not blanch (turn white) under pressure, it is a Stage 1 pressure injury.

In patients with darker skin tones, erythema may not be visually apparent. Assess for localized changes in skin temperature, tissue consistency, or sensation. A Stage 1 injury in darkly pigmented skin is often identified by palpation — the area feels different from surrounding tissue — before it is identified visually.

Documentation Requirements

Document the anatomic location over the bony prominence, the size of the affected area in centimeters, the description of skin changes (color, temperature, moisture, turgor), the blanchability test result, and any pain the patient reports. Photograph with a ruler or measurement reference in frame.

Treatment Protocol

Stage 1 is the prevention stage. The injury is reversible if pressure is eliminated immediately.

Repositioning every 2 hours for bed-bound patients, every 1 hour for chair-bound patients. Document each turn with time and position.
Pressure redistribution — foam overlays or pressure-reducing mattresses (Group 1 support surfaces). Heel elevation with pillows or commercial heel suspension devices.
Skin protection — moisture barrier cream if incontinence is a factor. Avoid massage over the affected area — this damages fragile capillary beds.
Friction reduction — use draw sheets for repositioning. Never drag the patient across bed linens.
Nutritional screening — initiate dietary review. Even at Stage 1, nutritional optimization accelerates tissue recovery.

If the erythema does not resolve within 72 hours of consistent pressure elimination, reassess the staging and escalate the care plan.

Stage 2: Partial-Thickness Skin Loss

Clinical Criteria

Stage 2 presents as partial-thickness loss of dermis, appearing as a shallow open ulcer with a red-pink wound bed, without slough. It may also present as an intact or ruptured serum-filled blister. This stage involves the epidermis and part of the dermis — the damage does not extend into subcutaneous tissue.

Stage 2 should not be used to describe moisture-associated skin damage (incontinence-associated dermatitis), skin tears, medical adhesive-related skin injuries, or tape burns. These have distinct etiologies and require different treatment pathways.

Documentation Requirements

Document wound dimensions (length, width, depth in centimeters), wound bed description (color, tissue type, presence or absence of blister), wound edges (attached, unattached, rolled), periwound skin condition, exudate type and amount, and the etiology confirming pressure as the cause. Note the bony prominence involved. Document what differentiates this from a moisture lesion if incontinence is present — auditors will question the staging if both pressure and moisture exposure exist without a clear differential assessment.

Treatment Protocol

Moisture management — hydrocolloid dressings or transparent film dressings to maintain a moist wound environment. Avoid wet-to-dry dressings — they damage the fragile wound bed.
Shear protection — protect the wound from friction during repositioning. Apply skin protectant to periwound area.
Continue q2h repositioning with documentation of each turn. Elevate heels completely off the bed surface if the injury is on the heel.
Support surfaces — Group 1 pressure redistribution mattress if not already in place.
Nutritional targets — 30-35 kcal/kg/day, 1.2-1.5 g protein/kg/day. Supplement with vitamin C (250 mg BID) and zinc (220 mg daily) unless contraindicated.
Infection surveillance — monitor for signs of localized infection: increased pain, warmth, erythema spreading beyond the wound margin, purulent drainage, odor. Stage 2 injuries are not typically infected, but contamination during dressing changes is a risk.

Stage 3: Full-Thickness Skin Loss

Clinical Criteria

Stage 3 involves full-thickness tissue loss. Subcutaneous fat may be visible, but bone, tendon, and muscle are not exposed. Slough may be present but does not obscure the depth of tissue loss. Undermining and tunneling may be present.

The depth of a Stage 3 pressure injury varies by anatomic location. Wounds on the bridge of the nose, ear, occiput, and malleolus may be shallow because these areas lack subcutaneous tissue. In contrast, Stage 3 injuries over the sacrum or trochanter can be deep, with significant subcutaneous tissue loss.

Documentation Requirements

Full wound measurements including depth, undermining (documented by clock position and distance in centimeters), and tunneling if present. Wound bed tissue type percentages — what percentage is granulation, slough, necrotic. Exudate amount and character. Periwound assessment. Photograph with ruler. If debridement was performed, document the type (selective vs. excisional), tissue removed, instrument used, and the depth of tissue debrided.

Treatment Protocol

Stage 3 injuries require active wound management, not just prevention.

Debridement — remove necrotic tissue and slough to promote granulation. Selective debridement (97597/97598) for surface devitalized tissue; excisional debridement (11042+) when cutting into viable tissue to establish a clean wound bed. Document the method, depth, and tissue type removed per debridement billing requirements.
Negative Pressure Wound Therapy (NPWT) — Stage 3 injuries with adequate wound bed preparation are candidates for NPWT. Ensure the wound has been debrided of necrotic tissue before applying NPWT — placing a VAC on a necrotic wound bed is clinically inappropriate and will not meet LCD coverage criteria.
Nutrition optimization — 30-35 kcal/kg/day with 1.2-1.5 g protein/kg/day minimum. Order prealbumin levels to track nutritional status objectively. A prealbumin below 15 mg/dL indicates severe protein depletion and impaired healing capacity. Supplement accordingly and recheck every 2-4 weeks.
Support surfaces — Group 2 support surfaces (powered pressure redistribution mattresses or low-air-loss mattresses) for Stage 3 injuries. Group 1 is insufficient for full-thickness tissue loss.
Repositioning — every 2 hours minimum, with pressure completely offloaded from the wound. Use 30-degree lateral tilt positions for sacral/coccygeal injuries. Document repositioning compliance.
Infection monitoring — wound cultures (preferably quantitative tissue biopsy or Levine technique swab, not routine wound swab) if signs of infection appear: increasing erythema, warmth, induration, purulent exudate, wound deterioration, fever, or elevated WBC. Topical antimicrobials (silver-based dressings, cadexomer iodine) for localized bioburden management.

Stage 4: Full-Thickness Skin and Tissue Loss

Clinical Criteria

Stage 4 involves full-thickness tissue loss with exposed or directly palpable bone, tendon, fascia, or muscle. Slough or eschar may be present on some parts of the wound bed. Undermining and tunneling frequently occur. The wound is deep, and the risk of osteomyelitis, sepsis, and other systemic complications is significant.

As with Stage 3, depth varies by location. Stage 4 injuries on the ear or nose may be relatively shallow but still expose cartilage. Sacral and ischial Stage 4 injuries can extend into the pelvic cavity.

Documentation Requirements

All Stage 3 documentation requirements apply, plus: document any exposed structures (bone, tendon, muscle, fascia) by name and location. Record undermining and tunneling with clock-face orientation and depth in centimeters at each position. Document probe-to-bone test results if osteomyelitis is suspected. Track wound progression (or deterioration) with serial measurements at consistent intervals. Photographic documentation at every visit is essential for Stage 4 claims — payers scrutinize these closely, and the photographic record must show the wound bed, exposed structures, and wound margins with measurement references.

Treatment Protocol

Surgical consult consideration — Stage 4 injuries that are not progressing with conservative management should be evaluated for surgical intervention: flap closure, myocutaneous flap, or direct closure depending on wound location, patient comorbidities, and surgical candidacy. Document the surgical consultation, the surgeon's assessment, and the rationale if surgery is deferred.
Osteomyelitis screening — perform a probe-to-bone test on all Stage 4 injuries near bony prominences. If the probe contacts bone, the positive predictive value for osteomyelitis is approximately 89%. Order MRI (preferred) or bone scan if probe-to-bone is positive. ESR and CRP support the clinical picture but are not diagnostic alone.
Aggressive debridement — excisional debridement (11043 for muscle/fascia involvement, 11044 for bone involvement) as indicated. Serial debridement is often necessary. Each session requires independent documentation of medical necessity.
NPWT — widely used for Stage 4 injuries with clean, granulating wound beds. Ensure LCD compliance for ongoing NPWT orders — LCD requirements mandate reassessment and re-justification at defined intervals.
Nutritional requirements — same targets as Stage 3 (30-35 kcal/kg, 1.2-1.5 g protein/kg) but enforce aggressively. Consider enteral supplementation if oral intake is insufficient. Monitor prealbumin, albumin, and weight trends.
Support surfaces — Group 2 powered surfaces mandatory. Low-air-loss or alternating-pressure mattresses. For patients who cannot be repositioned (e.g., hemodynamically unstable ICU patients), air-fluidized therapy beds may be indicated.
Infection control — systemic antibiotics for osteomyelitis or cellulitis extending beyond the wound margin. Topical antimicrobials for surface bioburden. Do not use systemic antibiotics for wound colonization alone — this promotes resistance without clinical benefit.

Unstageable: Obscured Full-Thickness Skin and Tissue Loss

Clinical Criteria

An unstageable pressure injury is a full-thickness wound in which the base is obscured by slough (yellow, tan, gray, green, or brown tissue) and/or eschar (tan, brown, or black necrotic tissue) to the extent that the true depth, and therefore the true stage, cannot be determined. Remove the slough or eschar and the wound becomes stageable — it will be either Stage 3 or Stage 4. Unstageable wounds are never Stage 1 or Stage 2.

The Stable Heel Eschar Exception

A critical clinical and billing distinction: stable eschar on the heel should not be debrided. If the eschar is dry, adherent, intact (no erythema, fluctuance, drainage, or odor), it serves as a natural biological cover for the underlying wound. Debriding stable heel eschar converts a protected wound into an open wound with exposed deep tissue — the opposite of a therapeutic outcome.

Document the eschar as stable and the clinical rationale for not debriding. "Stable heel eschar — dry, adherent, intact without signs of infection. No debridement indicated per NPUAP guidelines."

Documentation Requirements

Document that the wound bed is obscured, what is obscuring it (slough, eschar, or both), the percentage of wound bed covered, and why the wound cannot be accurately staged. Document the plan: autolytic debridement to gradually remove the obscuring tissue and allow staging, or observation if the eschar is stable (heels).

Treatment Protocol

Autolytic debridement — for wounds obscured by slough, apply moisture-retentive dressings (hydrogels, hydrocolloids) to promote the body's own enzymatic breakdown of necrotic tissue. This is a slow but controlled method that allows gradual wound bed exposure without aggressive intervention.
Enzymatic debridement — collagenase (Santyl) applied to slough-covered wounds to accelerate breakdown of devitalized tissue. Requires a prescription and is applied directly to the wound bed at each dressing change.
Do not debride stable heel eschar. Monitor for signs of instability: softening, drainage, erythema, fluctuance, odor. If any of these develop, the eschar is no longer stable and debridement is indicated.
Reassess staging as the wound bed becomes visible. Once the obscuring tissue is removed, assign the appropriate stage (3 or 4) and adjust the treatment plan accordingly.

Deep Tissue Pressure Injury

Clinical Criteria

Deep tissue pressure injury presents as a localized area of persistent non-blanchable deep red, maroon, or purple discoloration, or epidermal separation revealing a dark wound bed or blood-filled blister. The discoloration occurs over a bony prominence and results from sustained pressure and/or shear at the bone-muscle interface. The tissue damage originates deep — at the bone level — and works outward. The surface may appear deceptively intact while the underlying tissue is already necrotic.

This is the most unpredictable pressure injury category. A deep tissue injury can resolve without tissue loss, or it can rapidly evolve into a Stage 3 or Stage 4 wound as the damaged tissue declares itself over the following days to weeks.

Documentation Requirements

Document the exact location over the bony prominence, the skin color changes (use specific descriptors — "deep purple-maroon discoloration" rather than "bruise-like"), skin temperature, tissue consistency (boggy, firm, mushy), pain assessment, and any epidermal changes. Photograph at each assessment — the visual progression is the primary clinical and medicolegal record for deep tissue injuries.

Document the differential diagnosis. Deep tissue injuries must be distinguished from bruising (ecchymosis from trauma), Stage 1 injuries (which are erythematous, not purple/maroon), and vascular insufficiency lesions. The location over a bony prominence and the history of sustained pressure are the distinguishing factors.

Treatment Protocol

Close monitoring — assess every shift in acute care, every visit in outpatient or home health. Deep tissue injuries can evolve rapidly. The wound may look the same for days and then deteriorate within 24-48 hours as necrotic tissue separates.
Complete pressure elimination — offload the affected area entirely. Do not wait to see if it resolves before implementing full pressure redistribution. By the time a deep tissue injury is visible on the surface, the deep tissue damage has already occurred.
Do not debride prematurely. The full extent of tissue damage is not yet apparent. Allow the wound to declare itself. Premature debridement may open tissue planes unnecessarily. Reassess and stage once the injury evolves.
Support surfaces — Group 2 surfaces are appropriate given the severity of deep tissue involvement, even though the skin may appear intact.
Document evolution — serial measurements and photographs at each assessment, tracking whether the injury is resolving, stable, or deteriorating. If it deteriorates, restage as a Stage 3 or Stage 4 injury and adjust the treatment plan.

Support Surface Selection: Group 1 vs. Group 2

Support surface selection is driven by stage, risk level, and clinical presentation.

Group 1 (static) support surfaces include powered and non-powered pressure redistribution mattresses and overlays. Foam, gel, air, or water-based. These surfaces redistribute pressure but do not actively alternate pressure points. Appropriate for Stage 1, Stage 2, and prevention in patients with Braden scores of 14 or below.

Group 2 (dynamic) support surfaces include powered alternating-pressure mattresses and low-air-loss mattresses. These surfaces actively cycle pressure redistribution. Required for Stage 3, Stage 4, and any wound that fails to progress on a Group 1 surface. Also indicated for patients with multiple pressure injuries, patients who cannot be repositioned, and patients with Braden scores of 12 or below with documented failure on Group 1 surfaces.

Document the support surface type, the clinical justification for selection, and any upgrade from Group 1 to Group 2. Payers require medical necessity documentation for Group 2 surfaces — the claim must demonstrate that the patient's condition warrants the higher-level intervention.

Nutrition Protocol Across All Stages

Malnutrition is present in an estimated 50-70% of patients with pressure injuries. Nutritional deficiency directly impairs wound healing — collagen synthesis requires adequate protein, and cellular repair requires caloric fuel. No dressing, debridement, or support surface compensates for inadequate nutrition.

Caloric targets: 30-35 kcal/kg/day for patients with pressure injuries, adjusted for activity level and comorbidities. Patients who are underweight or catabolic may require the higher end of this range.

Protein targets: 1.2-1.5 g protein/kg/day. This is substantially higher than the standard 0.8 g/kg recommendation for healthy adults. Protein supplementation (oral supplements, fortified foods, or enteral nutrition) is typically necessary to meet this target in debilitated patients.

Micronutrients: Vitamin C (250 mg twice daily) supports collagen synthesis. Zinc (220 mg daily) supports immune function and cellular proliferation. Monitor for zinc toxicity if supplementation exceeds 40 mg elemental zinc daily.

Monitoring: Prealbumin (half-life 2-3 days) is the preferred marker for short-term nutritional status. Albumin (half-life 20 days) reflects longer-term trends but lags behind acute changes. Weight trends, dietary intake logs, and calorie counts provide the practical data.

Document the nutritional assessment, targets set, interventions ordered, and follow-up plan. A wound care plan without a nutrition plan is incomplete — and auditors increasingly treat it that way.

Infection Surveillance Across All Stages

Pressure injuries are colonized by definition — they are open wounds in proximity to perineal flora, skin bacteria, and environmental organisms. Colonization alone does not require treatment. Infection does.

Signs of localized infection: increasing pain, expanding periwound erythema, warmth, induration, purulent or malodorous drainage, wound deterioration despite appropriate care, and friable or discolored granulation tissue.

Signs of systemic infection: fever, elevated WBC, tachycardia, altered mental status, sepsis criteria. Systemic signs in a patient with a Stage 3 or Stage 4 pressure injury warrant blood cultures and consideration of osteomyelitis workup.

Culture technique matters. Surface swabs grow colonizers, not pathogens. If wound infection is suspected, use the Levine technique (rotate swab over 1 cm squared area of clean wound bed with enough pressure to express tissue fluid) or quantitative tissue biopsy. Report to the provider with specific organisms and sensitivities.

Document infection surveillance findings at every wound assessment. A clean wound note states "no signs of clinical infection" — not silence on the topic. Silence suggests the assessment was not performed.