疾病的发生与个体因素、环境因素及病原因素有关。个体因素中主要的是性别、年龄、种族、免疫、遗传等。近年在各发达国家中,外因性疾病激减,相反成人病却增加,尤其是在日本人死因中占有重要比例的高血压、脑卒中、心肌梗塞等,被认为与遗传因素有关,研究循环 The occurrence of diseases and individual factors, environmental factors and pathogenic factors. The main individual factors are gender, age, race, immunity, genetic and so on. In recent years, in developed countries, extrinsic diseases have been greatly reduced, while adult diseases have increased. In particular, hypertension, stroke and myocardial infarction occupy an important proportion of the Japanese cause of death, and are considered to be related to genetic factors. Research cycles