A patient with lower limb atherosclerosis occlusive disease who had smoked for thirty years was treated with interventional therapy in our vascular surgery department last year, which opened up the blood vessels and completely improved his symptoms. As a result, after returning home, he did not control his smoking habit and smoked secretly, and was hospitalized again a few days ago. A cigarette can really have such a great harm? Studies have shown that smoking causes sympathetic excitation, vasoactive substances increase, causing vasospasm and endothelial cell damage. Smoking also increases plasma viscosity and fibrinogen, enhances platelet activity, increases platelet aggregation, and causes arterial stenosis. Smoking affects lipid metabolism, increases the content of cholesterol in the blood, makes the blood sticky, and aggravates limb ischemia. With the improvement of people’s living standard and dietary structure, the incidence of atherosclerotic vascular disease is increasing. Many elderly people suffer from atherosclerosis to varying degrees, which is a systemic disease. Atherosclerotic plaques blocking blood vessels can spread to the heart, brain, kidneys and extremities, with arteriosclerotic occlusive disease of the extremities being the most common. Can cause limb ischemia, cold, numbness, pallor, pain and other symptoms, resulting in gangrene of the limbs and even life-threatening, the disease 80% and smoking-related. Recently, the state promulgated the Rules for the Implementation of the Regulations on Public Health Management, which means that the new rule of “no smoking in indoor public places” is officially effective. As early as last year, our hospital became a “smoke-free hospital” and established a “smoking cessation clinic”. May 31 every year is “World No Tobacco Day”, let’s keep away from the harm of tobacco from you and me.