(1)Different constitutions are vulnerable to different diseases. For example, those with superabundant Yang and deficient Yin will be vulnerable to wind and heat pathogens and less vulnerable to cold and damp pathogens. Those with insufficient body fluid and blood will be vulnerable to dryness and less vulnerable to dampness.
(2)Different constitutions react differently to invasion by pathogens. In general, the weakest part of the constitution is most vulnerable. For example, Lung deficiency tends to lead to direct invasion of pathogens into the Lung meridian, which then develops into Lung disease. Liver deficiency tends to lead to direct invasion of pathogens into the Liver meridian, which then develops into Liver disease.
(3)The constitution type also decides disease nature. Superabundant Yang constitutions tend to develop heat syndrome after being invaded by pathogenic heat or pathogenic wind. Similarly, Yin-deficient constitutions tend to develop cold syndrome. Thus, within the same environment, different constitutions may develop different illnesses after being invaded by the same pathogen.
(4)Different personalities reflect the constitution’s spirit, possess different susceptibility, and may be sensitive to different pathogens. Generally, Yang personalities are susceptible to Yang pathogens (e.g. wind, heat) but not susceptible to Yin pathogens (e.g. cold, damp). Yin personalities are susceptible to Yin pathogens (e.g. cold, damp) but not susceptible to Yang pathogens (e.g. wind, heat).