Principles of the Occurrence of Disease
1. Disease--The Result of the "Struggle Between the Genuine-Qi and the Evil-Qi"
TCM holds that for the occurrence of all diseases, there must be certain causes
which are nothing more than the body's weak functional state, the low intensity of its resistance against disease, and attacks of various evils. Chapter 44 in Spirit Pivot says: "The occurrence of all diseases must be related with dryness, dampness, cold, heat, wind, rain, sexual intercourse, joy, anger, diet, and living place; and when the evil-qi meets with the genuine-qi, diseases will arise. The diseases are then given names according to the viscera involved. " Chapter 46 also says: "The reason why people frequently suffer from diseases is the looseness of their joints, skin, and muscular texture, which leads to attacks of the evils. " "When the evil-qi meets the genuine-qi, diseases will arise," refers to the fact that there will be fighting when the two kinds of factors meet,leading to the occurrence of disease.
The occurrence of disease is related to two aspects, namely the body's genuine-qi
and evil-qi. The genuine-qi refers to the functional activities of the body and its ability to prevent disease, struggle against disease, and repair injured tissues. The so-called evil-qi refers to various harmful factors that lead to diseases, such as the six climatic evils, seven motions, pestilential evils, phlegm, fluid retention, stagnant blood, and retention of the and drink taken into the body. So, TCM pathogenesis holds that the occurrence of any kind of diseases is nothing more than the actual reflection of the struggle between the gennine-qi and the evil-qi, the failure of the genuine-qi against the evil-qi, and of other contradictory struggles in the body.
Therefore, the occurrence of disease can be considered as a process in which the body's abilities of resisting diseases and repairing tissues struggle against the evil-qi. In this process, the internal unity of the body and the unity of the body and the external en vironment change continuously; but only when the body's genuine-qi becomes too weak to resist the evil-qi, or the intensity of the evil-qi attacking the body surpasses that of the genuine-qi defending the body, can diseases appear. This leads to the incoordination of zang-viscera and fu-viscera, yin and yang, and the qi and blood. It also results in disturbed physiological functions of the viscera and meridians and collaterals, together with lower adaptability to the external environment, thus leading to a decrease or loss of ability to live or work. The entire process of a disease, therefore, is the process of the struggle
between the genuine-qi and the evil-qi; and the inter-changes of the intensity of the genuine-qi and the evil-qi in this process are the basic factors directly affecting the development and prognosis of diseases.
2. "Deficiency of the Genuine-qi"--The Internal Cause of Occurrence of Disease
1) When the Genuine-Qi Keeps Itself Inside the Body, the Evil-Qi Will Be Unable to Attack
TCM pathogenesis pays special attention to the genuine-qi of the human body, and
deems that under normal conditions, if the genuine-qi is strong, or the evil-qi is weak,the body is resistant to attack by the evils, and the body can remain free from disease even though it is being attacked by the evils.
The explanation is that, in this case, the contradictory movement of yin and yang,qi and blood, viscera and meridians and collaterals is still within the scope of physiological development and changes, and thus enables the genuine-qi to resist the evil-qi. To this point, Chapter 72 in Plain Questions says: "When the genuine-qi keeps itself inside the body, the evil-qi will be unable to attack. " Synopsis of the Golden Chamber also says; "If the body is not in a weak state, the evil-qi will have no chance to enter the interspace of fresh. "
However, if the genuine-qi and the resistance against disease are too weak to resist the evil-qi, or the evil-qi is great in its intensity, the evil-qi will get a chance to attack the body, causing the body's contradictory movement to go beyond the scope of physiologica changes and development, and leading to the functional incoordination of the zang-viscera and fu-viscera, yin and yang, and qi and blood. Genuine-qi will be unable to resist the evil-qi; and diseases will result.
2) When the Evil-Qi Gets a Chance to Attack the Body, the Body's Genuine-Qi Must Be Weak
TCM pathogenesis holds that the weak state of genuine-qi is the basis of the occurrenee of diseases, while the evil-qi is the condition of the occurrence of diseases. The genuine-qi in a weak state includes two aspects: First, a low visceral ability to prevent and resist diseases and to repair the injured tissues~ and second, the relatively weak state of the genuine-qi caused by the intensity of the evil-qi surpassing its defensive ability. Both of these aspects cause the evil-qi to invade the body and lead to the incoordination of the zang-viscera and fu-viscera, and yin and yang, qi and blood, from which diseases appear.
Though the occurrence of disease is related to both the genuine-qi and the evil-qi, it is the genuine-qi that plays the decisive role in the occurrence of disease. Only when the genuine-qi becomes weak can the evil-qi invade the body and cause disease. To this point, chapter 66 in Spirit Pivot says:"If the genuine-qi is not in a weak state the evil-qi, such as wind, rain, cold, and heat, is unable to cause damage to the body. The reason why a person does not catch disease even though he suddenly suffers a strong wind and heavy rain is that his genuine-qi is not weak and the evil-qi is unable to attack his body. On the contrary, if the body is impaired by the evil-qi, the genuine-qi of the body must be weak, which gives a chance for different evils to launch their attack. " Chapter 33 in Plain Questions also says: "When the evil-qi has launched a successful attack on the body, the genuine-qi must be weak. " Special attention must be paid to the state of the genuine-qi. Therefore, it can be said that TCM pathogenesis regards the intensity of the genuine-qi
as the basis of the occurrence of disease.
It can be seen that the viewpoint of "struggle between the genuine-qi and the evilqi" emphatically explains that the basic cause of the occurrence of disease is not the external pathogenic factors, but is the body's internal contradictory state and incoordination of yin and yang, qi and blood, zang-viscera and fu-viscera, and meridians and collaterals.
3. The Evil-Qi--The Important Condition of Disease
TCM attaches importance to the genuine-qi and pays greater attention to its leading ro1e in producing diseases. But it should also be pointed out that TCM pathogenesis does not deny or rule out the importance of the evil-qi in the occurrence of disease. Although the evil-qi is a condition of the occurrence of disease, it may even play a leading role in producing diseases under certain circumstances. For example, burns by high temperature, bullet wounds, and bites by insects or beasts, result in injury to the body even though the genuine-qi is strong. Chapter 72 in Plain Questions clearly points out the infectivity of the "pestilential evils", and the same chapter also points out that to prevent the attack of the pestilential evils, besides "strengthening the genuine-qi," "isolation measures must be adopted," especially in cases of strong pestilential evils which under cerrtianconditions can play an important pathogenic role, and may even lead to epidemic spread.
TCM pathogenesis, therefore, not only regards the weak genuine-qi of the body
the basis of the occurrence of disease, but also pays attention to the importance of the evil-qi; this dialectical pathogenic theory agrees with the clinical practice, and is clearly different from the metaphysical viewpoint of putting undue emphasis on externa pathogenic factors.
It must be pointed out that the purpose of correctly understanding the occurrence and development of diseases is to prevent and treat diseases. With an understanding that the occurrence of disease is due to attacks launched by the evil-qi when the genuine-qi is in weak state, clinical prevention and treatment of diseases should begin with strengthening the genuine-qi of the body and dispelling pathogenic conditions by doing something to improve the external environment. At the same time, physical exercise with the purpose of strengthening the body's resistance against disease should also be adopted.
