Thrombo-occlusive vasculitis, referred to as TAO, as the name suggests, is related to vascular occlusion, Chinese medicine as early as 2000 years ago, there is a discussion, “issued in the toes, the name off carbuncle, its appearance of red and black, death is not treated, not red and black, not dead, not decay, urgent chopping, not is dead carry on”, Chinese medicine called “gangrene “. Vasculitis and arteriosclerosis, diabetes and Raynaud’s disease caused by vascular disease is different, mostly in 20-45 young adults smoking men, women only 5%, is the limb arteries mainly inflammatory, segmental and periodic episodes of chronic occlusive disease, less involved in the heart, brain, kidneys and other organs. Causes: The exact cause of thrombo-occlusive vasculitis has not been confirmed, but is generally thought to be related to cold, infection, smoking, hormones, etc. Cold can cause vasospasm, resulting in inflammatory degeneration of the trophoblastic vessels in the blood vessels, thickening of the intima, and thrombosis. Smoking and thrombo-occlusive vasculitis have a close relationship, there is experimental confirmation that tobacco contains nicotine can prompt vasoconstriction, in vasculitis patients, smokers account for the vast majority of the disease occurs in young and middle-aged men. The main manifestations: wandering phlebitis: about 40% of patients have a history of wandering phlebitis. Usually peanut-sized red, hot and painful nodules appear in the superficial veins of the foot or lower leg, which can subside on their own after a period of time, and then appear elsewhere. Pain: Pain is a common and shared symptom of vascular disease. 90% of patients present with pain at an early stage and is the main reason for patient visits, mainly caused by ischemia or necrosis of the limb due to inadequate blood supply to the limb. The main manifestations are intermittent and persistent pain. Intermittent claudication: It is the early symptom of ischemia, but it is easily ignored by the patient. It is manifested as; after the patient walks a certain distance at a certain speed, that is, spasms of pain, soreness, twitching, weakness and other symptoms appear in the muscles behind the calf, and cannot continue to walk, and after a short rest in place, the pain can be relieved and the patient can continue to walk again, but the above symptoms appear again after walking. Persistent pain: also known as resting pain, the pain is often more severe, meaning that the degree of ischemia is severe and necrosis has occurred or is imminent in the fingers or toes. Patients feel persistent dull pain in the hands and toes with intermittent sharp stabbing pains accompanied by coldness at the ends of the fingers (toes), fear of cold and abnormal sensations such as numbness, burning and pins and needles. The pain is often worse at night and is more intense if there is already limb necrosis, which directly affects rest and sleep. Change in skin color and temperature: Due to insufficient blood supply, the skin color of the fingers or toes may change, and the blood supply may become pale or even greenish-purple. The damaged hand, foot or finger (toe) has a positional color change, and the skin temperature of the limb is reduced and feels cold. Changes in peripheral arterial pulsation: The pulsation of peripheral arteries such as the dorsalis pedis, posterior tibial artery, radial artery, ulnar artery may be weakened or absent in patients with vasculitis, and in severe cases, the pulsation of the N artery and femoral artery may be difficult to palpate. Ulceration and necrosis: In mild cases, only one finger or toe may be involved, but in severe cases, multiple toe (finger) ulcers or extensive necrosis are often present.