Bedsore stages explained: what do stage 1, 2, 3 and 4 mean?

The stages

• Stage 1: intact skin with a persistent red area (on darker skin, a color or texture change) that does not turn white when pressed.
• Stage 2: partial-thickness skin loss: a shallow open wound or an intact or broken blister.
• Stage 3: full-thickness skin loss with fat visible. There may be tunneling under the edges.
• Stage 4: full-thickness skin and tissue loss with exposed or palpable muscle, tendon, ligament, cartilage or bone. High risk of bone infection (osteomyelitis) and sepsis.
• Unstageable: the base is covered by slough (yellow, tan or gray) or eschar (black or brown), so the true depth cannot be seen. Once cleaned, these are usually stage 3 or 4.
• Deep tissue pressure injury: a persistent deep red, maroon or purple area, or a blood-filled blister, from damage to underlying tissue. These often open into deep wounds.

Where they form

Over bony areas that bear weight: the tailbone (sacrum and coccyx), buttocks, hips, heels, ankles, elbows, shoulder blades, and the back of the head and ears.

What the rules require

Federal rules require nursing homes to ensure that a resident does not develop a pressure injury unless the resident's condition made it clinically unavoidable, and that a resident with one receives the treatment needed to promote healing and prevent infection. The facility must document that it assessed risk and carried out prevention before claiming a wound was unavoidable.

Watch the progression

Wound records should show weekly measurements and descriptions. A wound that keeps getting larger or deeper, a stage 2 that becomes a stage 4, or a wound first documented at stage 3 or 4 (meaning earlier stages were missed) are serious warning signs.