Most data affirm that smoking is a risk factor for stroke. Prospective studies in the United States and Japan have demonstrated that the mortality rate among smokers is 1.4 times higher than that of non-smokers in cerebrovascular disease aged 55 to 64 years. The risk of stroke in heavy smokers (40 cigarettes/day) was twice as high as that in light smokers (10 cigarettes/day). It has been suggested that smoking lowers HDL-cholesterol ratio and increases total serum cholesterol, which aggravates atherosclerosis and reduces cerebral blood flow. The decrease in cerebral blood flow was 12.5% in male smokers compared to non-smokers, and the decrease in cerebral blood flow was more pronounced with age, probably because smoking aggravates atherosclerosis and increases vascular stenosis and resistance. Recent studies have concluded that smoking increases the risk of cerebrovascular disease because: 1, smokers have high concentrations of carbon monoxide in the body, which can cause increased permeability of the vascular wall, making it easy for lipoprotein deposits in the plasma to occur in the vascular wall and atherosclerosis. 2, long-term smoking can cause the vascular wall cells prostaglandin-like substances (can dilate the blood vessels) to reduce, vasoconstriction, platelet aggregation, coagulation mechanism is impaired. Long-term smoking (more than 10 years, 20 cigarettes / day), can promote the development of occlusive cerebrovascular disease. 3, tobacco contains nicotine-like substances, which can increase the plasma adrenaline content, causing an increase in heart rate and blood pressure. Smokers who also suffer from hypertension, the chance of cerebrovascular disease is 20 times higher than that of nonsmokers.