Four stages of pressure ulsers
Stage 1- nonblanchable erythema signaling potential breakdown.
Stage II- partial thickness, skin loss, (abrasion, blister or shallow crater involving epidermis & possibly the dermis.
Stage III- Full-thickness skin loss involving damage or necrosis that may extend down to, but not through underlying fasia.
Stage IV- full-thickness skin loss with tissue necrosis or damage to muscle, bone, or supporting structures such as tendon or joint capsule