病因

流行病学中的病因一般称为危险因素，含义是使疾病发生概率即危险升高的因素。

Modern epidemiology中这样解释cause：One definition of the cause of a specific disease occurrence is an antecedent event, condition, or characteristic that was necessary for the occurrence of the disease at the moment it occurred, given that other conditions are fixed. In other words, a cause of a disease occurrence is an event, condition, or characteristic that preceded the disease onset and that, had the event, condition, or characteristic been different in a specified way, the disease either would not have occurred at all or would not have occurred until some later time.