The Principle of Reducing the Surplus and Supplementing the Deficient Is the Fundamental Principle of TCM Treatment

In the book Laozi (Dao De Jing) there is a famous maxim: the Way of Heaven reduces the surplus and supplements the deficient. Traditional Chinese medicine (TCM) is especially closely linked to Daoist philosophy; Laozi's idea of reducing the surplus and supplementing the deficient can be said to be the fundamental principle of TCM in treating disease. TCM holds that excess must be driven out and deficiency must be supplemented - that is, the surplus pathogenic excess is removed through sweating, emesis and purgation, while the deficiency of insufficiency is replenished by various treatments that support the vital upright qi. In this way the body can ultimately reach the balanced state of yin calmed and yang secured, and that balanced state is the state of an ordinary person who can live free of illness.

How does one tell whether a person is in a state of insufficiency or of surplus? This must be judged by comprehensively analysing the person's physical signs and pulse. Any physical signs or pulse tending toward weakness indicate a state of deficiency; any tending toward excessiveness indicate a state of surplus. When TCM selects a treatment principle, it acts on the patient according to these signs and pulses of surplus and deficiency.

In TCM pattern differentiation, the single most important principle is distinguishing yin patterns from yang patterns. A yin pattern is a condition of deficiency; a yang pattern is a condition of surplus, or of excess. The yin-pattern patient is quiet and reluctant to speak, feeble and slack, with a pulse that is deep, slow, fine and weak; the yang-pattern patient talks much and is easily angered, restless and agitated, with a pulse that is exuberant and forceful. The signs of surplus and of deficiency are utterly distinct, and the drug-using principles differ by heaven and earth. If a patient with a surplus pattern is given large formulas that support upright qi, it will surely aid the rising power of the pathogen; if a patient with a deficiency pattern is given pathogen-expelling drugs, it will bring about a great decline in the patient's strength.

Yet distinguishing surplus from deficiency is by no means easy. Some patients present simultaneously with signs of both, being excessive in some respects and deficient in others. Or a condition originally of surplus may, through long neglect of treatment, gradually consume the original qi, presenting the complex picture of a deficiency of original qi together with an excess of pathogen. Then one must simultaneously attend to supporting upright qi and expelling the pathogen. Supporting upright qi nurtures the patient's original qi; expelling the pathogen removes the patient's disease evil. Only by combining the two can a good therapeutic effect be obtained. The proper intensity of expelling the pathogen versus supporting upright qi is remarkably hard to judge, and it is precisely here that a doctor's skill is tested.

Some renowned ancient TCM physicians of outstanding efficacy would often support upright qi one day and attack the pathogen the next, or support upright qi for several days and then attack the pathogen for several days. The late elderly Shanxi TCM physician Men Chun-de often prescribed two formulas, A and B, for patients with upright deficiency and pathogen excess: Formula A for supporting upright qi and Formula B for expelling the pathogen, taken on alternating days. Such a method can be called ingenious; it is exactly the embodiment of the TCM spirit that "the subtlety of application lies entirely within the mind."

For diseases such as cancer, which present as conditions of great surplus and great deficiency, treatment must consider using upright-supporting and pathogen-expelling measures together: supporting upright qi to raise the patient's immunity, and expelling the pathogen to attack the patient's cancer tumour. Only by working on both sides at once can one both preserve the patient's life and treat the disease. If one merely writes a bland peaceable formula to support the patient's upright qi, one has only briefly deceived the patient's body within a year or two - or even less - letting the patient feel comfortable while slowly walking toward death. Such treatment resembles boiling a frog warm: the frog is slowly cooked to death without ever realizing it. If, on the other hand, one only fiercely attacks the pathogen without regard for the patient's capacity to endure, the patient's crisis may arrive in an instant. But if attack and supplementation are combined, and their intensity well judged, then even a patient whose illness is grave and hard to save may, with the doctor's help, extend his life by many years, and may even survive long-term while carrying the cancer.