The causes of sudden death are mostly related to cardiac or cerebrovascular diseases, such as acute myocardial infarction, large coronary artery blockage, sudden cardiac death and cardiac arrest. In addition, hypertrophic cardiomyopathy, which is a hereditary cardiomyopathy, usually occurs suddenly after exercise and is mainly caused by malignant arrhythmias. Diseases of the nervous system, such as massive cerebral infarction in the brainstem or cerebral hemorrhage, can cause sudden death, so normal people without underlying heart disease or cerebrovascular disease will not experience sudden death.