Classification of Decubitus Ulcers (after Daniel)

• Stage I: non-blanchable redness of the skin, which may be hotter than normal, but shows no lesions.
  
  
• Stage II: the epidermis is damaged. In this stage, the ulcer may be referred to as a blister or abrasion.
  
  
• Stage III:  involves the full thickness of the skin and may extend into the subcutaneous tissue layer. Muscle and bone tissue are not yet affected. A deep wound develops.
  
  
• Stage IV: is the deepest, extending into the muscle or even bone.