Nursing care
Pressure Injury Staging: the method, the errors, and the exam
Written and reviewed by Dana Whitfield, RN, MSN · 5 min read · Updated September 2026
Short answer
Pressure injury staging classifies skin damage by depth: Stage 1 is intact skin that is non-blanchable, Stage 2 is partial thickness, Stage 3 extends into subcutaneous fat, and Stage 4 exposes muscle, tendon, or bone. A wound covered by black eschar cannot be staged until it is debrided, because the true depth is hidden underneath.
What the skill is for
Staging tells the care team how deep the tissue damage goes, which drives the treatment plan, the support surface ordered, and how the wound is expected to progress. It is also a documentation and reimbursement matter: an inaccurately staged pressure injury misrepresents the patient's condition on the record and can misdirect wound care resources.
The skill matters most at admission, when the nurse must determine whether a pressure injury was present on arrival or developed during the stay, and at every subsequent assessment, when a wound can move deeper as tissue continues to break down. Staging is not a one-time label; it is reassessed each time the wound is examined.
The method, step by step
Start by cleaning the wound bed so you are looking at actual tissue, not dried exudate or debris. Examine the wound for intact skin versus open skin, then assess depth: is it limited to the epidermis, does it reach the dermis, does it extend into subcutaneous fat, or does it expose muscle, tendon, joint capsule, or bone.
Stage 1 is intact skin with non-blanchable redness, meaning the area does not turn white when pressed. Stage 2 is partial thickness, presenting as a shallow open wound or an intact or ruptured blister, with no slough. Stage 3 is full thickness with visible fat but no exposed bone, muscle, or tendon. Stage 4 is full thickness with exposed muscle, tendon, or bone. If the wound bed is obscured by slough or eschar so depth cannot be confirmed, it is unstageable rather than assigned a numbered stage.
Where it goes wrong
The most common error is staging by appearance alone without confirming what lies beneath. A wound covered by thick, adherent black eschar looks superficial from the surface, but the tissue underneath may already be full thickness. That wound is unstageable until debridement reveals the wound bed, and calling it a Stage 2 or 3 by guesswork is a documentation error with real consequences for the care plan.
A second error is confusing a pressure injury with other wound types, such as a moisture-associated skin injury or a venous ulcer, which are staged and treated differently. A third is staging over a suspected deep tissue injury, where the surface looks like a bruise but signals damage that has already occurred below intact skin — this is documented as its own category, not folded into Stage 1.
Practising it deliberately
Build a mental checklist you run through every time: is the skin intact, is it blanchable, how deep does it go, and can I actually see the wound bed. Practise verbalising this sequence out loud during simulation or clinical rounds until it becomes automatic rather than something you reconstruct from memory under pressure.
Use photographs of each stage side by side and quiz yourself on the distinguishing feature of each, rather than trying to memorise a paragraph description. The distinguishing feature for Stage 1 is non-blanchable redness on intact skin. For Stage 2, no slough is present. For Stage 3, fat is visible but not bone. For Stage 4, bone, muscle, or tendon is exposed. For unstageable, the depth is hidden.
Applying it on the exam
NCLEX questions on pressure injury staging typically describe a wound in narrative form and ask you to identify the stage, or they describe a scenario and ask what the nurse should do first. Read for the depth clue: mentions of fat, muscle, tendon, or bone tell you the stage directly, while a description of eschar or thick slough should make you think unstageable before you think about numbering it.
Watch for distractor answers that stage a wound based on size rather than depth. A large but shallow wound is still Stage 2 if it has not passed the dermis, and a small deep wound can be Stage 4. If a question presents a wound covered in black eschar and asks you to select a stage, the correct answer is that it cannot be staged until debrided, not a numbered guess.
A worked example
A patient who has been immobile for several days has a sacral wound. On inspection, the skin is intact but a two-centimetre area is deep red and does not blanch when pressed with a gloved finger. There is no open skin, no blister, and no visible fat, muscle, or bone. This is Stage 1: the skin is intact, and the defining feature is non-blanchable erythema.
Now change the finding: the same area is covered by a thick, dry, black, firmly adherent eschar, and the wound edges beneath it cannot be visualised. Even though the surface area is similar to the first example, this wound is unstageable, because the eschar hides whatever depth of damage lies beneath it. The correct nursing action is not to assign a stage but to refer for debridement so the true extent can be assessed.
The next step on this is the same as on everything else here: answer questions and read the rationales. Our med-surg practice questions are the closest set to what this page covers.
One question from the med-surg set
A client with chronic obstructive pulmonary disease has an oxygen saturation of 88% on 2 L/min via nasal cannula and is alert with no distress. What should the nurse do first?
Rationale
In COPD a saturation of 88–92% is the therapeutic target, not an emergency, and this client is alert with no distress. The first action is the independent nursing intervention that is least invasive and most likely to help: sit them up and reassess. Turning the oxygen up to 6 L/min risks blunting the hypoxic drive, and calling rapid response or drawing an ABG escalates ahead of an assessment you have not finished.
Answer: B
Common questions
What makes a pressure injury Stage 1 rather than just skin redness?
Stage 1 is intact skin with erythema that does not blanch when pressed, meaning the redness stays even under direct pressure. Ordinary reactive redness from pressure blanches and fades quickly once pressure is relieved, which is a normal finding rather than a Stage 1 pressure injury.
Why can't a wound covered in eschar be staged?
Black eschar is dead tissue that obscures the wound bed, so the nurse cannot see whether the damage stops at the dermis, extends to fat, or reaches muscle or bone. The wound is documented as unstageable until debridement exposes the actual depth.
What is the difference between Stage 3 and Stage 4?
Stage 3 is full-thickness tissue loss with visible subcutaneous fat but no exposed muscle, tendon, or bone. Stage 4 is full-thickness loss with muscle, tendon, or bone exposed or directly palpable.
Is a deep tissue injury the same as a Stage 1 pressure injury?
No. A suspected deep tissue injury presents as intact or non-intact skin with a persistent, non-blanchable area of deep red, maroon, or purple discolouration, often looking like a bruise, and signals damage to underlying tissue that has already occurred. It is documented as its own category rather than as Stage 1.
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