[Comparative study on the academic thought of bloodletting for expelling pathogens between Jin-Yuan Dynasties and Ming-Qing Dynasties].

The relevant provisions of bloodletting for expelling pathogens are collected from the works of the medical representative scholars in Jin-Yuan Dynasties and Ming-Qing Dynasties respectively to construct the databases of bloodletting for expelling pathogens of Jin-Yuan Dynasties and Ming-Qing Dynasties. Using frequency analysis, the bloodletting device, bloodletting location, bloodletting volume, the related pathogens and indications are compared between these two times so that the evidences could be provided for the inheritance and development of the academic thought of bloodletting for expelling pathogens. It is found that the three-edge needle is the most commonly used device for bloodletting in Jin-Yuan Dynasties and Ming-Qing Dynasties and meridians and local affected area are generally selected for bloodletting. The range of meridian and acupoint selection in Ming-Qing Dynasties are more extensive than those in Jin-Yuan Dynasties, while bloodletting volume is less than that in Jin-Yuan Dynasties. In Jin-Yuan Dynasties, bloodletting therapy is mainly for expelling exogenous pathogens i.e. heat, fire and wind, while, in Ming-Qing Dynasties, this therapy is specially for clearing heat and removing stasis. The disorders of internal medicine are often treated with such therapy in these two dynasties. But, compared with Jin-Yuan Dynasties, the indication of bloodletting therapy is expanded gradually in Ming-Qing Dynasties. It is shown that the academic thought of bloodletting for expelling pathogens in Jin-Yuan Dynasties is inherited and developed from Ming-Qing Dynasties.