Most of the lower extremity ulcers are venous ulcers, but one needs to be alert to ulcers from other causes as well. The following diseases need to be identified: 1. Tuberculous ulcers, called tuberculous sores in Chinese medicine, often have a history of tuberculosis in other parts of the body. The lesion is initially a reddish-brown papule with a deep central necrotic ulcer, with a jagged submerged edge, and septicemia-like pus can be observed, with a peri-sore purple color ulcer stubbornly persisting for a long time. Patients with longer disease duration can observe alternating old and new scarring, which can leave depressed pigment after healing, and such ulcers need to be combined with anti-TB treatment to be effective; 2. The edge of the ulcer is crater-like, rolled up irregularly, hard to touch and light gray in color, and its base is easy to bleed, and the cancerous ulcer is difficult to heal; 3.radioactive ulcer, with obvious radiation burn-like, the lesion is confined to the radiation site, and there are often multiple small ulcers fused into one, and the surrounding skin is pigmented or interspersed with small white spots, and there is obvious stiffness of the damaged skin and the base.