Difficulty 22

The medical classic states: In the channels, there are "shi dong" (movement disorders) diseases and "suo sheng bing" (generated diseases). The same channel manifests as two different diseases—why is this?

It is answered: What the medical classic calls "shi dong" is a disease of the qi aspect; "suo sheng bing" is a disease of the blood aspect. When the pathogenic factor is in the qi aspect, abnormality in the qi aspect forms the "shi dong" disease; when the pathogenic factor is in the blood aspect, abnormality in the blood aspect forms the "suo sheng bing". Qi governs warming and nourishing; blood governs moistening and enriching. When qi stagnates and cannot move, it is the qi that first becomes diseased; when blood becomes obstructed and cannot nourish, it is the blood that later becomes diseased. Therefore, the "shi dong" disease appears first, and the "suo sheng bing" disease appears later.