Unstageable wounds cannot be staged due to eschar or slough covering the wound. The wound bed must be visualized in order to stage the wound. Stage I ulcers have intact skin with a red area. The area may be firm, painful, soft, or cooler or warmer compared to adjacent tissue. Stage II ulcers present with partial thickness loss of dermis and a red-pink wound bed. No slough is present. Stage III ulcers have full-thickness skin loss and may contain slough. The wound may have visible subcutaneous tissue, and tunneling and undermining may or may not be present. Stage IV ulcers present with full-thickness skin loss and exposed bone, muscle, or tendons. Eschar and slough may be present, and tunneling and undermining may develop.