Over-rest means lack of enough activity. Protracted lack of enough activity will lead to slow movement of qi and blood, hypofuncton of the viscera, poor appetite, fatigue, dispiritedness, weakness of the four limbs or obesity, intolerance to work, palpitation, asthma and sweating when moving. Prolonged lack of activity will give rise to the production of phlegm, dampness and blood stasis inside the body and invasion of pathogenic wind, cold and dampness from the outside, eventually binging on various diseases.

Phlegm and blood stasis are pathological substances produced during the course of disease due to certain pathogenic factors. They may directly or indirectly affect the viscera and the body, leading to secondary disease. So phlegm and blood stasis are both pathological substances and pathogenic factors. Since they have resulted from primary disease, they are called secondary pathogenic factors.