Mechanism of pathological changes
Mechanism of pathological changes includes the nature of disease and its transmitting principles. The occurrence of disease results from the struggle between pathogenic factors and healthy qi which exists in the whole course of disease. In the struggle between pathogenic factors and healthy qi, various general or local pathological changes will be caused if healthy qi is impaired, the balance between yin and yang is damaged, the functions of meridians are in disorder and the flow of qi and blood is disturbed. Though complicated, pathological changes generally can be classified into such categories as predomination and decline of pathogenic factors and healthy qi, imbalance of yin and yang as well as disorder of qi, blood and body fluid.