There are several main reasons for the formation of cerebral infarction: First, the thickening of the vessel wall and narrowing of the lumen caused by atherosclerosis, and the distal small vessels will be in a state of occlusion, causing ischemia and hypoxia in brain tissue, leading to necrosis of brain cells and causing damage to brain function. Second, the embolism factor, due to the large atherosclerotic plaque off, with the blood flow to its diameter of the brain vessels when the phenomenon of embolism, blocking the cerebral vessels, so that blood flow interruption caused by cerebral infarction. Third, some patients have fat embolism, air embolism and amniotic fluid embolism, etc., which can cause cerebral infarction. Fourth, the factor of blood viscosity, patients can be dehydrated, hyperthermia, diarrhea and fractures, resulting in increased blood viscosity; or patients with hyperfibrinogenemia, true erythrocytosis, will also lead to increased blood viscosity, slow blood flow, clotting will occur and cause cerebral infarction.