Thromboembolic vasculitis occurs in young and middle-aged men, most of them have a history of smoking, half of them have wandering superficial phlebitis and Raynaud’s sign, and some of them exist at the same time, and the lesion spreads to the middle and small arteries in the end parts of upper and lower limbs, which is cyclic and staged development. There is intermittent claudication in the early stage, resting pain in the middle and late stage, and gangrene of the toes (fingers) is the main symptom, especially the toes. 1, occlusive atherosclerosis occurs in middle-aged and old age, patients often have hyperlipidemia, hypertension, coronary heart disease, diabetes mellitus, as well as fundus retinal and systemic atherosclerosis manifestations, signs of arterial occlusion of the limbs are obvious, lesions are often dominated by the large and medium-sized arteries, and vascular murmur can be heard at the stenosis site. The development is slow, the clinic can appear intermittent claudication, rest pain or even gangrene, angiography or CT scan can be performed to help diagnosis. Acute arterial embolism The clinical manifestation of acute arterial embolism varies with the plane and severity of obstruction, and is also related to the establishment of collateral circulation. Acute limb ischemia manifests as pulselessness, pain, pallor, coldness, paralysis, and sensory abnormalities. The skin in the ischemic area may appear bruised, and if it does not change color when pressed, gangrene may develop, which is an advanced stage of ischemia. Further development can also appear blisters, after the loss of skin moisture is typical of dry gangrene, combined with infection can also be seen wet gangrene. 3.Multiple aortitis Mostly seen in young women, 2/3 of the patients have fever, myalgia, fatigue and loss of appetite in the early symptoms. Vascular lesions are mainly in large vessels, and vascular murmurs can be heard in narrowed areas. Symptoms of ischemia are: pulselessness, dizziness, panic, blurred vision, black haze in front of the eyes, and hypertension, renal failure and so on. 4, diabetic vascular disease According to the statistics of diabetic patients over 50 years old, the occurrence of limb gangrene is 15 times higher than the normal population. 40% of diabetic foot lesions are caused by neuropathy, because peripheral neuropathy can cause sensory retardation, limb sensitivity decline is a potential threat to patients with diabetes mellitus. In diabetes, aortopathy is characterized by intermittent claudication, rest pain, and gangrenous ulcers. About 1/3 of diabetes mellitus is associated with neuropathy and abnormal sensations, including heat, pain, cold and numbness. Diabetic gangrene is characterized by wet necrosis.