Root and Branch
In the process of the occurrence and development of a disease, there are always primary and secondary contradictions; and the primary contradiction or the primary aspect of a contradiction is the “root”, while the secondary contradiction or the secondary aspect of a contradiction is, comparatively speaking, the “branch”. The “root” has a dominating effect on the “branch”; while the “branch” is subdominant to the “root”. When the genuine-qi and evil-qi are being discussed, the genuine-qi is “root” while the evil-qi is “branch”; when the cause of disease and its symptoms are discussed, the cause is “root” while its symptoms are “branch”; when pathological sites discussed, viscera’s pathogenic change is “root”, while that in the superficial parts of the body are “branch”; when the order of occurrence of disease is discussed, old illness is “root”, while newly occurring illness is “branch”; and finally, primary illness is “root”, while secondary illness is “branch”.

Treating Barnch First

Treating Branch First in Emergency Cases: If a serious complication takes place in the developing process of a disease, this complication, although a branch, is an emergency and should be resolved promptly; otherwise it will endanger the patient’s life or hinder the treatment of the root (the primary disease). In this condition, doctors ought to apply the principle of treating the branch first in emergency cases. For example, in the case that a patient with a chronic disease has newly suffered exogenous evil, the newly developed disease is urgent, one must dispel the exogenous evil (treating the branch) first; and only when the exogenous syndrome is cured, can the chronic disease be cured (treating the root).

Treating the Root

Treating the Root in Less Urgent Cases: In ordinary conditions, doctors must seize the essence of a disease, administer treatment against the root cause of the disease, and resolve the basic contradiction. For instance, pulmonary tuberculosis is, according to TCM theories, a syndrome with symptoms such as cough, low fever, dry mouth and throat, hot sensation in the five centers, red cheek and night sweat. These symptoms are induced by yin deficiency and endogenous heat, and by the deficiency fire injuring the lung. The symptoms are branch, while yin deficiency, endogenous heat, and the lung injured by fire are root. So one ought to nourish yin and moisten the lung to resolve the contradiction of yin deficiency. Only by improving the body’s resistance to disease, can this syndrome be cured.

Treating Branch and Root

Treating Branch and Root Simultaneously: When both branch condition and root condition are serious and urgent, one should treat the root and branch at the same time. For example, febrile disease with exogenous heat invades into the interior of the body, leading to interior syndrome which lasts for a long period of time and consumes body fluid. These pathogenic changes induce symptoms such as fullness, hardness, and pain in the abdomen, constipation, fever, dry mouth and chapped lips, and scorched coating of the tongue. In this case, the genuine-qi is deficient, the evil is excessive, and both the branch condition and root condition is urgent, so one should give consideration to both the root and branch, by administering both purgative therapy and yin nourishing therapy at the same time. That is to treat the root by purging the excess heat, and to treat the branch by nourishing yin and replenishing the body fluid.