How do I stage pressure ulcers (PrU)?

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Last updated: March 28, 2025View editorial policy

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From the Guidelines

Pressure ulcers are staged using a four-stage classification system based on the depth of tissue damage, with additional categories for unstageable and deep tissue pressure injuries, as recommended by the American College of Physicians guideline 1.

Staging Classification

The staging classification system is as follows:

  • Stage 1: intact skin with non-blanchable redness in a localized area, usually over a bony prominence
  • Stage 2: partial-thickness skin loss with exposed dermis, appearing as a shallow open ulcer with a red-pink wound bed without slough
  • Stage 3: full-thickness skin loss where subcutaneous fat may be visible but bone, tendon, and muscle are not exposed
  • Stage 4: full-thickness skin and tissue loss with exposed bone, tendon, or muscle

Additional Categories

There are also two additional categories:

  • Unstageable pressure injuries: full-thickness skin and tissue loss with the base covered by slough or eschar, preventing direct visualization of the wound bed
  • Deep tissue pressure injuries: localized area of persistent non-blanchable deep red, maroon, or purple discoloration

Assessment and Documentation

When assessing pressure ulcers, it is essential to:

  • Clean the wound thoroughly before staging
  • Document the location, size, depth, presence of undermining or tunneling, wound bed appearance, exudate, and surrounding skin condition Accurate staging is crucial for developing appropriate treatment plans and monitoring healing progress, as emphasized in the American College of Physicians guideline 1.

From the Research

Staging Pressure Ulcers (PrU)

To stage pressure ulcers, it is essential to follow the updated staging system of the National Pressure Injury Advisory Panel 2, 3. The revised staging system uses Arabic numerals to denote stages and describes the extent of tissue loss present and the anatomical features that may or may not be present in the stage of injury.

Key Considerations

  • Pressure injuries are localized damage to skin or soft tissue, commonly occurring over bony prominences 2.
  • Comprehensive skin assessments are crucial for evaluating pressure injuries 2.
  • The revised definition of a pressure injury describes the injuries as usually occurring over a bony prominence or under a medical or other device 3.
  • Each definition now describes the extent of tissue loss present and the anatomical features that may or may not be present in the stage of injury 3.

Clinical Practice Guidelines

  • The European Pressure Ulcer Advisory Panel, the Pan Pacific Pressure Injury Alliance, and the National Pressure Ulcer Advisory Panel have updated the 'Prevention and Treatment of Pressure Ulcers: Clinical Practice Guideline' (CPG) in 2019 4.
  • The 2019 guideline update builds on the previous 2014 version to ensure consistency and comparability 4.
  • A systematic review of clinical practice guidelines and other best practice recommendations for pressure injury risk assessment in the United States found that risk assessment was consistently positioned as a critical first step in the prevention of pressure injuries 5.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Revised National Pressure Ulcer Advisory Panel Pressure Injury Staging System: Revised Pressure Injury Staging System.

Journal of wound, ostomy, and continence nursing : official publication of The Wound, Ostomy and Continence Nurses Society, 2016

Research

A systematic review of clinical practice guidelines and other best practice recommendations for pressure injury risk assessment in the United States.

Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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