Chinese medicine’s view of the onset of the disease that the positive qi has a dominant role in the development process, and as a reflection of the positive qi characteristics of the body, often affects the occurrence of disease, development and change. The role of constitution in the onset of disease, specifically expressed as follows: 1, determining the disease evidence, the constitution is the embodiment of positive qi, and thus determines the tendency of the disease. Generally speaking, the physique is strong, the resistance to disease is also strong, not easy to sense evil disease; or although the internal and external evil disturbed, easy to tend to real evidence. Weak body, it is easy to sense the onset of disease, after the onset of disease, easy to tend to mixed evidence of deficiency, or false evidence. 2, decided to susceptible to certain diseases and evils of different physiques, the essence of yin and yang are different, on certain diseases and evils have different susceptibility to certain diseases have different susceptibility to certain diseases. Yang deficiency of the body, each easy to feel the cold; Yin deficiency of the quality, each easy to feel the heat. Children’s organs delicate, shape gas is not full, and vigorous, rapid development, so susceptible to external evils, or injuries to the diet or susceptible to heat after the sense of evil wind, or susceptible to growth and development disorders. Older people, dirty gas has been loss, insufficient essence and blood, resistance to disease, regulation, recovery have declined, susceptible to external evil and the onset of the disease, the evidence is prone to the formation of mixed evidence of deficiency, or false evidence, and more delayed and difficult to cure. Women take blood as the basis, with menstruation, belt, fetus, childbirth physiological changes, also has a certain impact on the development of disease, easy to disease liver depression, blood deficiency, blood stasis; men take essence as the basis, easy to suffer from kidney essence and kidney qi deficiency of disease. Fat people or phlegm-damp body, susceptible to cold and dampness, prone to dizziness, stroke; thin people or Yin deficiency, susceptible to dry heat, susceptible to consumption and cough. 3, to determine the type of disease symptoms feel the same disease, due to different individual constitution, can show different types of symptoms. If you feel the wind and cold evil, the Wei Qi is rich, it is easy to form a solid evidence; Wei Qi is weak, it is easy to form a false evidence or false mixed evidence. The same sense of dampness, the body of Yang Sheng is easy to heat into the formation of damp-heat certificate; Yang deficiency is easy to cold into the cold and wet certificate, this is called “from the chemical”. On the other hand, if the body is the same, although the feeling of different diseases and evils, can also show the same type of symptoms. For example, a hot body can show hot symptoms regardless of whether it feels heat or cold.