There are three major causes of cerebral infarction: 1, atherosclerosis leads to narrowing of blood vessels or plaque shedding, blocking blood vessels causing interruption of blood supply to brain tissue caused by risk factors including hypertension, diabetes, hyperlipidemia, smoking, etc. These factors lead to atherosclerosis and thus cause cerebral infarction death; 2, is the heart source of emboli blocking cerebral vessels causing cerebral infarction death, the most common related heart disease is The most common related heart disease is atrial fibrillation or atrial fibrillation, and others include heart valve lesions, endocarditis, myocardial infarction, etc. can increase the risk of brain infarction death; 3, the small blood vessels of the brain itself cause blockage, patients tend to infarction area is relatively small, symptoms tend to be relatively mild. Other is the rare causes of brain infarction death, such as erythrocytosis, arterial entrapment, vasculitis, etc. For relatively young patients without obvious vascular risk factors, we should focus on finding these possible rare causes.