In the Ming Dynasty, Zhang Jiebin divided cough into two categories: exogenous and internal injuries. "Cough" pointed out: "Cough is a syndrome, and it is too complicated to see a family's arguments, and it is not necessary, which makes future generations do not know what to do in the clinic, so it is difficult to cure it. If you look at the rest, you will have to cough, but only two syndromes. What is the second certificate? One day's exogenous factors are exhausted by one day's internal injuries ... But in the two, we should distinguish between yin and yang, and distinguish between false and true ears. "