病机之名，首见于《素问·至真要大论》的“审察病机，无失气宜”和“谨守病机，各司其属”。在现代，“病机”一词的解释具有浓厚的现代医学气息，“病机”就是“病理”，但病机之“机”与机理显然不是同一含义。对“病机”的认识之所以没有达成共识，争论的焦点就在于对“病机”中“机”的认识，“机”引申义多达20余种。在《内经》中，“机”的应用达30多处，含义也比较多，从字面上讲，《内经》中所说的“病机”的“机”为机要，关键点之意，“病机”意为“疾病病变的关键点”。结合上下文语境理解病机，五脏六腑的虚实改变，风寒暑湿燥火的虚实真假是疾病病变的关键点，就是病机。概括而言，《内经》病机理论可大致分为两类，一类是纲领性病机理论，概括了疾病病因、病性、病位等特性要素；一类是具体疾病的病机理论，是对疾病全程疾病属性的概括。

The word 'Pathogenesis' appeared first as "when examining the Pathogenesis, gas Yi is the key" and "Pathogenesis roots in its own causes" in Plain Questions o Medical Classics. In modern days, the term is defined to mean pathology in modern medicines, apparently, as the result of the influence of modern medicines. However, as far as definition is concerned, Pathogenesis in traditional Chinese medical theory is different from the Pathogenesis in modern medicines. People have so far reached no consensus on this, as Ji may have up to 20 extended explanations. For example, Ji was used extensively in Canon of Internal Medicine, for as many as 30 times, for different connotations. Literally speaking, Ji means a key point of disease, and "pathogenesis" the key points of a disease in Canon of Internal Medicine. Clinically, however, having the knowledge of the basic points of a disease is not sufficient. To work out a sound judgment of pathogenesis, one has to identify not only the basic points of the disease, but also the deficiency and sthenia of five internal organs, and the flow of winds, cold, dampness, fire, and heat. Specifically, when a disease occurs, both the deficiency and sthenia change in one's five internal organs. In this context, the flows of winds, cold, dampness, fire, and heat are the key points of lesions.