Smoking is an independent risk factor for hemiplegia. Cigarettes contain a large amount of nicotine, and the nicotine inhaled into the body when smoking causes the adrenal glands to release epinephrine and norepinephrine, causing vasoconstriction or spasm and increased resistance to blood flow, resulting in damage to the blood vessel wall, while the release of epinephrine can prompt platelet aggregation, platelets also tend to adhere to the damaged arterial wall, and platelets are released from the hemiplegic rehabilitation department of Sichuan Province Eight Rehabilitation Center Zhu Gao platelets The release of platelets and aggregation of platelets makes vasoconstriction, resistance increases, and blood viscosity further increases. The study found that the aortic wall of quitters is thicker than that of never smokers, and, the longer people smoke, the more they smoke, the thicker the aortic wall becomes. In addition, the carotid artery walls of people who quit smoking are also thicker than those of nonsmokers, and the thickness is also proportional to the duration of smoking and the number of cigarettes smoked. Smoking can cause an increase in blood viscosity, such as an increase in erythrocyte pressure product, high whole blood viscosity, a significant increase in low-shear rate and reduced viscosity, and a decrease in erythrocyte deformability and increased aggregation. Long-term smoking can lead to chronic carbon monoxide poisoning, because the affinity of carbon monoxide for hemoglobin is more than 200 times higher than that of oxygen, which changes the dissociation curve of oxygen and increases the affinity of hemoglobin, so hypoxia increases the production of red blood cells, resulting in an increase in red blood cell pressure. Ischemic hemiplegia is a non-specific disease with multiple etiologies, but its common feature is the increase in blood viscosity. Smoking has been shown to cause significant increases in blood viscosity and vascular wall damage, which predispose to the onset and progression of hemiplegia. The pathological process of hemiplegia due to smoking is that as the time of smoking increases, the amount of smoking increases, the blood viscosity increases and gradually reaches a certain threshold, the body is in crisis, and the ability of auto-regulation decreases, leading to the occurrence of hemiplegia.