Chronic trauma is currently classified in a confusing way, and there is no systematic way to classify it. It can be generally classified as venous, arterial, diabetic, traumatic, and pressure. The classification method varies according to the trauma caused by different diseases. For example, diabetic chronic trauma can be divided into vascular, trophic and mixed types. Chronic trauma of the lower extremity can be divided into pressure ulcers of the lower extremity and vascular ulcers of the lower extremity. In addition, diabetic chronic trauma can be divided into stage zero, stage I, stage II, stage III, stage IV, stage V, etc. Pressure ulcers can also be divided into five stages.