- Stage 1 (Grade 1): Skin is intact, but there’s persistent redness (or darker discoloration) that doesn’t turn white when pressed (“non-blanchable”). Area may feel warm, firm/soft, or painful/itchy.
- Stage 2 (Grade 2): Partial-thickness skin loss. Looks like a shallow open sore or a blister (may be intact or broken). Involves the outer skin layers but not deeper tissue.
- Stage 3 (Grade 3): Full-thickness skin loss. The ulcer goes through the skin into the fat layer. It can look like a deeper “crater,” and there may be dead tissue (slough), but it doesn’t reach muscle or bone.
- Stage 4 (Grade 4): Full-thickness skin and tissue loss with deep damage. The ulcer extends to muscle, tendon, or bone, and often includes dead tissue and a high risk of serious infection.
Quick note: Sometimes ulcers are labeled “Unstageable” (base covered by dead tissue so you can’t see how deep it is) or “Deep tissue pressure injury” (dark purple/maroon area or blood-filled blister from damage under the skin).
