Giving prevention the priority means to take measures to prevent the occurrence of disease. Since the occurrence of disease is related to insufficiency of healthy qi and attack of pathogenic factors, the preventive measures taken should focus on reinforcing healthy qi and preventing the invasion of pathogenic factors by means of regulating psychological state, diet and living habit as well as doing physical exercise. Besides, cares should be taken to avoid attack of pathogenic factors.

Regulating psychological state covers three aspects: avoiding direct damage of the viscera and disturbance of qi and blood; avoiding invasion of pathogenic factors due to deficiency of healthy qi caused by psychological factors; protecting and cultivating healthy qi to further strengthen Constitution. There are various ways to regulate psychological state, the general principle is to be free from avarice. If one keeps the mind tranquil, qi and blood will flow normally, yin and yang in the body can communicate freely with that in the natural world, which can not only prevent the invasion of pathogenic factors but also strengthen constitution.

      

Diet provides necessary nutrients for the body, but unhealthy eating habits and improper food (such as intemperance or starvation, unhygienic food and food partiality) impair the viscera and damage harmonious state of qi and blood. To cultivate health through regulating diet can supplement essence, adjust the state of yin and yang, improve constitution and strengthen body resistance. There are various ways to cultivate health through regulation of diet, these methods should be applied according to individual conditions. The general principle is to eat regularly at the right time in proper proportions with hygienic eating habits.

Proper living habits include regular work and rest, temperance in sexual activity and proper clothing in different seasons. Proper living habits are effective in abiding by the variations of yin and yang in the natural world, protecting the viscera, qi, blood and body fluid, and preventing invasion of pathogenic factors.

      

Exercising the body can promote the flow of qi and blood, reinforce the functions of the viscera and prevent retention of pathogenic factors. There are various ways to exercise the body. However traditional ways to exercise the body are more effective for strengthening constitution, eliminating disease and prolonging life, such as Wuqinxi (five-animals frolics), Baduanjin (eight-sections exercise), Yijinjing (tendon-relaxing exercise) and Taijiquan (taiji box), etc. 

These traditional exercises are slow in action and general in relaxation, very effective for directing the flow of qi and blood. They combine static actions with dynamic activities, effective for regulating both yin and yang without damaging tendons and exhausting qi and blood. People with different constitution should select different exercise.

     

Since pathogenic factors are the key elements in causing disease, measures have to be taken to avoid the attack of pathogenic factors in the cultivation of healthy qi. Some pathogenic factors are very toxic, even strong constitution cannot resist them. Thus the avoidance of these pathogenic factors is the only way to prevent the occurrence of disease.

When disease has occurred, it may transmit from a local area to the viscera and other regions. In this case, measures have to be taken to stop such transmission and change.

At the early stage, disease is easy to treat because it is still light and healthy qi has not declined yet. However, delayed treatment may worsen the disease and make it difficult to treat due to transmission of pathogenic factors from the external to the internal and damage of healthy qi. If healthy qi is seriously impaired and pathogenic factors become more and more predominant, the disease is hard to treat and tends to become aggravated. So early treatment is very important.

       

Transmission and change refer to movement and change of disease in the external and the internal, the upper and the lower, the zang-organs and the fu-organs, the meridians and the collaterals, wei, qi, ying and blood phases. The transmission and change of disease follow certain rules and routes. Measures can be taken according to these rules and routes to prevent the transmission and change of disease in advance.

The method for controlling the transmission and change of disease is to regulate and nourish the organs or areas that the disease is liable to transmit to by means of reinforcing healthy qi to prevent the transmission of the disease. For example, it is said in Jingui Yaoliie "measures must be taken to strengthen the spleen in the treatment of liver disease because liver disease tends to transmit to the spleen." 

That means to invigorate spleen-qi to prevent liver disease from transmitting to the spleen. Take febrile disease for another example. Since pathogenic heat damages yin, the impairment of stomach-yin can damage kidney-yin. Under such a condition, the prescription composed herbs sweet in taste and cold in nature for nourishing the stomach can be added with some herbs salty in taste and cold in nature for nourishing kidney-yin in order to prevent pathogenic heat from impairing the kidney.