Appendix 5. Classification of Pressure Ulcer Clinical Symptoms

Grade	Definition
Stage 1	Erythema of skin- Red and dry skin in the area under pressure, slightly feverish, mild edema or tenderness, limited to inflammatory changes in the skin's surface.
Stage 2	Ulcer of skin- As inflammatory reactions spread to the dermis and subcutaneous tissues, the skin is dark red, resulting in subcutaneous osmosis, resulting in mild infection.
Stage 3	Necrosis of skin- As the skin is necrotized, the ulcer is formed, resulting in an infection.
Stage 4	Necrosis of tissueThe tissue is necrotic, black, stenchy, ulcers can form up to the deep layer of the skin, ligaments or bones, and has a moderate infection, which is usually caused by bacillus pyocyaneus or staphylococcus aureus.