Three kinds of pathogenic factors
  Three kinds of pathogenic factors The classification of pathogenic factors in ancient times which include the endogenous, exogenous and the neither endogenous nor exogenous pathogenic factors. Endogenous factors primarily refer to the feelings or psychological influences on the mind, which include joy, anger, anxiety, pensiveness, grief, fear and fright. Exogenous factors are seasonal influences or climatic variations of nature that include wind, cold, summer-heat, dampness, dryness and fire. Neither of the above two are all types of chance mishap and include intemperance, fatigue, trauma and presence of parasites in the body.
san yin 三因