Bedsore Stages: Understanding Pressure Injury Stages 1 Through 4

Your loved one has a bedsore. The nurse used a number – “It’s a Stage 2” or “We’re watching a Stage 3.” But what does that mean? How bad is it? And how bad can it get? A meta-analysis of over 355,000 nursing home residents found that 11.6 percent develop pressure injuries, with 8.5 percent acquired during their nursing home stay [PubMed 37801939]. Each stage means different things for your loved one’s health, recovery, and care. This guide explains them all.

Understanding bedsore stages helps you recognize how serious your loved one’s wound is. If they developed a pressure injury in a nursing home, a free case evaluation can help you understand your rights.

Find Out If It Was Preventable

How Bedsore Staging Works

The National Pressure Injury Advisory Panel (NPIAP) classifies bedsores into four numbered stages, plus two additional categories: unstageable and deep tissue pressure injury. The stages describe how deep the wound goes.

Higher stages mean deeper damage, harder treatment, and worse outcomes. Here is what the data shows for healing:

• Stage 2: Approximately 70 percent heal within six months [NBK553107]
• Stage 3: Approximately 50 percent heal within six months [NBK553107]
• Stage 4: Approximately 30 percent heal within six months [NBK553107]

Each stage that a wound reaches makes recovery significantly harder.

The three most common body sites for bedsores are the heel (34.1 percent), sacrum or lower back (27.2 percent), and foot (18.4 percent) [PMC12599044].

Stage 1: Non-Blanchable Redness

A Stage 1 bedsore is the earliest form of pressure injury. The skin is intact – not broken – but there is persistent redness over a bony area that does not fade when you press it [NPIAP / PMC5098472].

Non-blanchable erythema means the tiny blood vessels under the skin have been damaged. The tissue is already injured, even though it looks like “just redness.”

What you see: A red or discolored patch of skin over the heel, hip, lower back, or other bony area. The skin feels warm or firm.

On darker skin: Stage 1 is harder to detect. Redness does not show the same way on darker skin tones. Look for deep brown, gray, or purple discoloration, and check for warmth, firmness, and pain [PubMed 37590446]. Clinicians should use the SADS framework for assessment.

Healing outlook: With immediate pressure relief, Stage 1 injuries typically resolve in 7 to 14 days. But 35.5 percent deteriorate to Stage 2 or deeper even when repositioning protocols are applied [PMC7951350].

Read the full Stage 1 guide

Stage 2: Partial-Thickness Skin Loss

A Stage 2 bedsore means the skin is broken. The wound has gone partway through the skin, exposing the dermis (the layer under the surface). It may appear as a shallow pink or red open wound, or as an intact or ruptured blister filled with clear fluid [NPIAP].

What you see: A shallow wound with a pink or red base, or a blister. The wound bed is alive (viable). There is no dead tissue (slough) in a true Stage 2.

Important: A blister with dark, purple, or maroon coloring may actually be a deep tissue injury, not a Stage 2. Deep tissue injuries have a far worse prognosis.

Healing outlook: About 70 percent heal within six months. Median healing time is 46 days. Stage 2 is the critical window – healing is still straightforward with proper care.

Read the full Stage 2 guide

Stage 3: Full-Thickness Skin Loss

A Stage 3 bedsore goes through all layers of skin. Fat tissue is visible in the wound bed. The wound may have granulation tissue (bumpy, reddish healing tissue) and rolled edges. Slough or eschar (dead tissue) may be present [NPIAP / PMC5098472].

What you see: A deep, crater-like wound. Yellow fat tissue is visible. Dead tissue may be yellow, tan, or black. The wound may have drainage and odor.

Key distinction from Stage 4: Bone, muscle, and tendon are NOT visible or palpable. If they are, the wound is Stage 4.

Note: Some body areas – the bridge of the nose, ears, back of the skull, and ankle bones – cannot develop Stage 3 because they do not have enough fat tissue.

Healing outlook: About 50 percent heal within six months. These wounds carry a 2.4 times higher mortality risk.

Read the full Stage 3 guide

Stage 4: Full-Thickness Tissue Loss

A Stage 4 bedsore is the most severe stage. The wound goes through all layers of skin into the structures underneath. Fascia, muscle, tendon, ligament, cartilage, or bone is exposed or directly palpable [NPIAP / PMC5098472].

What you see: A deep wound where you may see bone, muscle, or tendon. Yellow, brown, or black dead tissue is common. Heavy drainage and foul odor are typical. The wound may be wider underneath than it appears at the surface (undermining) or have narrow passages extending outward (tunneling).

Healing outlook: Only about 30 percent heal within six months. Only 5 percent close within eight weeks under standard care. Patients with Stage 4 wounds face a 2.4 times higher mortality risk [PMC7949299].

Read the full Stage 4 guide

Unstageable Pressure Injury

An unstageable pressure injury is a wound where dead tissue covers the wound bed so completely that the true depth cannot be determined. The wound is covered by slough (yellow, tan, or gray tissue) or eschar (black or brown dried tissue) [NPIAP].

The wound is at least Stage 3. It may be Stage 4. But until the dead tissue is removed through debridement, no one can see how deep it goes.

An unstageable wound requires debridement to determine its true severity.

Deep Tissue Pressure Injury (DTPI)

A deep tissue pressure injury appears as persistent, non-blanchable deep red, maroon, or purple discoloration on intact or broken skin [NPIAP / PMC5098472]. It indicates damage at the bone-muscle level from prolonged pressure and shear.

This is one of the most dangerous categories because the surface may look minor while the damage underneath is severe. A small dark area on the skin can hide extensive destruction of deep tissue.

DTPI can evolve rapidly. What looks like a minor bruise-like area can open into a Stage 3 or Stage 4 wound within days.

The Rule Against Reverse Staging

The NPIAP has a clear rule: bedsore stages cannot be used in reverse [NPIAP 2017 Position Statement]. A wound that started as Stage 4 and is improving does NOT become “Stage 3” and then “Stage 2” as it heals. The correct way to document a healing wound is “healing Stage 4” throughout.

This matters because the body fills a Stage 4 wound with granulation tissue and scar tissue – not with new muscle, bone, or fat. The wound may close, but the tissue is not the same as what was lost.

If you see a medical record that says a wound went from Stage 4 to Stage 2, that documentation is incorrect. It may indicate that the facility does not understand proper wound staging. Incorrect staging can also mask how serious the original injury was, which matters if you are evaluating the quality of care your loved one received.