I burns Only the superficial epidermis is injured, and the hair growth layer is alive with erythematous, dry, burning sensation on the surface, which heals in 3~7 days with flaking and pigmentation in the short term Shallow II burns Injury to the hair growth layer of the epidermis and the papillary layer of the dermis with obvious local redness and swelling, with blister formation After blister formation and exfoliation, the wound surface is red, moist and painful, and if there is no infection, it heals in 1~2 weeks without scarring, and most have pigmentation Deep II burns Injury to the skin The dermis layer can have blisters, blisters peel off the trauma surface slightly moist, red and white, pain is dull with residual skin attachment, if there is no infection, can be fused repair takes 3 ~ 4 weeks, and there is often scar growth Ⅲ burns The whole skin layer or even reach the subcutaneous, muscle or bone trauma surface without blisters, such as leather-like, under the scab vascular embolism pain disappears except for small area burns, often need to be implanted scar growth is obvious.