Chronic ulcers of the lower extremities are ulcers that have not healed for more than one month, called chronic ulcers of the lower extremities, and are a common disease in surgical practice. There are many causes of chronic lower extremity ulcers, such as ulcers caused by peripheral vascular disease, radiation cauterization ulcers, ulcers caused by chemotherapy, nerve injury ulcers and so on. Among them, the most common are chronic ulcers of the lower limbs caused by peripheral vascular diseases, which can be divided into venous ulcers and arterial ulcers according to the different causes. The majority of chronic ulcers in the lower limbs are venous ulcers. For the different causes, we should prescribe the right medicine and take the corresponding treatment method to be effective. Therefore, it is necessary to understand the causes of ulcer formation before treatment in order to be able to target them. How to distinguish venous ulcers from arterial ulcers? The so-called venous ulcers are ulcers caused by venous lesions in the lower extremities, commonly caused by varicose veins in the lower extremities, primary or deep vein thrombosis in the lower extremities followed by venous valve insufficiency in the deep veins and traffic branches of the lower extremities. This eventually leads to venous stasis in the lower extremities, long-term venous hypertension, skin dystrophy, skin ulcers that do not heal over time, or repeatedly ulcerate after healing, and long-term ulcers that do not heal may become cancerous. In Chinese medicine, it is called “polyposis”, commonly known as “old rotten feet”. Arterial ulcers are ulcers caused by arterial lesions in the lower extremities, commonly caused by lower extremity arteriosclerosis occlusive disease, thrombo-occlusive vasculitis, and vascular diabetic foot ulcers. The main cause is severe narrowing or occlusion of the arteries in the lower extremities, causing necrosis and ulceration due to insufficient local blood supply, and in severe cases, amputation of the limbs (toes). Chinese medicine is called “gangrene”. 2, the onset of the site is different venous ulcers occur more in the lower 1/3 of the lower leg to the ankle; arterial ulcers occur more in the end of the limb, that is, the foot, the end of the toe. 3. The accompanying symptoms are different. Venous ulcers are mostly accompanied by swelling of the calf or ankle, which is light and heavy at night, or the patient feels that the affected limb is sore and heavy after standing and walking for a long time, and is relieved after resting or elevating the affected limb; in addition, the skin of the calf can be accompanied by changes such as pigmentation, skin itching and eczema. Arterial ulcers are often accompanied by coldness and numbness in the extremities, decreased skin temperature, and severe pain in the extremities or lower extremities, which is aggravated at night and when the temperature drops. The ulcer usually goes through a phase of intermittent claudication and resting pain before the ulcer occurs. 4.Different concomitant diseases and family history Patients with venous ulcers mostly have a family history of varicose veins in the lower extremities, as well as a history of long-term standing work. Patients with arterial ulcers are often accompanied by hypertension, hyperlipidemia or diabetes, as well as a long-term history of smoking. In clinical practice, there are also many patients with coexisting arterial and venous lesions, so the presentation and nature of ulcers are not as typical and easy to identify as described above. For different causes of ulcers, etiologic and symptomatic treatment, combination of primary and secondary treatment, Chinese and Western medicine can have better results. For example, ulcers caused by varicose veins in the lower limbs can be treated by simple and effective modern minimally invasive surgery for varicose veins and diseased traffic branch veins to relieve venous stasis and venous hypertension in the lower limbs, thus promoting ulcer healing. Ulcers caused by arteriosclerosis-occlusive disease of the lower extremities and diabetic foot can be treated by endovascular treatment to dilate the narrowed arteries and open the occluded arteries to restore blood supply and promote ulcer healing. At the same time, TCM treatment can promote the establishment and opening of collateral vessels, increase local blood supply, reduce or control the progress of vascular occlusion; and reduce the recurrence of the disease. The so-called allopathic treatment means that according to the different conditions of the sore surface, different TCM characteristic external treatments (such as fumigation therapy, wrapping therapy, patching therapy, etc.), characteristic TCM topical medicines (myogenic powder, Huanglian liquid, red oil cream, etc.), and different drug exchange methods (such as TCM decay cleaning, TCM dragline therapy, etc.) are used to accelerate the healing of ulcers.