Patients with cerebral infarction should not smoke, and smoking is an important risk factor for the occurrence of cerebral infarction. Smoking increases the incidence of cerebral infarction, and patients with cerebral infarction who smoke are 2.5 times more likely than those who do not smoke. If a smoker also has high blood pressure and high blood sugar, the chances of having a cerebral infarction are even higher. Smoking increases the concentration of carbon dioxide in the body, which shortens the myosin in the endothelial cells of the arteries and increases the permeability of the blood vessel walls. The common carotid artery and the internal carotid artery are the two most frequent sites of atherosclerosis blockage, followed by a decrease in cerebral blood flow, which has a direct impact on the blood supply to the skull and brain and eventually causes cerebral infarction. Smoking causes a decrease in blood flow to the gray matter of the brain, a corresponding decrease in prostaglandins and other substances in the vascular cells, vasoconstriction, and the formation of platelet collections in the blood, causing cerebral infarction to occur. In addition, smoking also tends to cause occlusive arteriosclerosis and thrombo-occlusive vasculitis. Therefore, smoking is very harmful to cerebral infarction.