Zhang Xichun is a famous doctor in modern China. It can be seen from his book

Records of Chinese Medicine with Reference to Western Medicine

(

yī xué zhōng zhōng cān xī lù

) that he has a profound and unique understanding of the causes and pathogenesis of Bi (impediment) and Wei (flaccidity) diseases. His concurrent treatment of Bi and Wei diseases was elaborate in its development of treatment method and use of drugs. Deficiency of great qi (

dà qì

) is the pathogenesis basis of Bi diseases and the basic condition of Wei diseases

and original qi is the root of great qi. Qi stagnation and blood stasis is the direct cause of Bi and Wei diseases

and it is closely related to the spleen

liver and kidney. Therefore

Zhang Xichun treated the two types of disease in a simultaneous fashion. He laid emphasis on invigorating original qi and great qi

and regulating stagnation of qi and blood. If qi stagnation and blood stasis is dominant

special attention should be paid to promoting the flow of qi and blood. In addition

Bi and Wei diseases are mostly manifested in the limbs

but also the viscera should be regulated

and different medicinals should be chosen according to the location of the disease. This study summarizes Zhang Xichun’s insights into the etiology and pathogenesis of Bi and Wei diseases and his experience in treatment to guide clinical practices.