My Medical Philosophy: The TCM Treatment System of "Principle, Method, Formula, and Medicinal"

Traditional Chinese medicine (TCM) treats disease by following a step-by-step progression through the four levels of "principle, method, formula, and medicinal."

The highest-level principle, put simply, is "reduce what is in excess, supplement what is insufficient," adjusting the body from a state of either "excess" or "deficiency" back toward balance. As stated earlier, this balanced state corresponds to the TCM ideal of "yin calm and yang secured, the spirit thus harmonized," and it closely resembles the Western medical concept of homeostasis.

The TCM "method" operates on two levels. One level is the "treatment principle" (zhi ze), that is, the guiding principle of treatment; the other is the "therapeutic method" (zhi fa), the concrete treatment approach worked out according to the principle.

TCM treatment principles embody an idea of neutralization, much like the chemical neutralization of acid and alkali. The chapter "On the Essentials of Truth" in the Huangdi Neijing (Yellow Emperor's Inner Canon) summarizes TCM treatment principles in the following passage: "In treating all excess and counterflow, cold syndromes are treated with heat, heat syndromes with cold, warm syndromes with cooling, cool syndromes with warming; dispersing conditions are astringed, restrained conditions are dispersed, dry conditions are moistened, urgent conditions are relaxed, hardened conditions are softened, fragile conditions are strengthened, depleted conditions are supplemented, and replete conditions are drained; each is restored to its proper qi, must be clarified and stilled, so that the disease qi declines and departs and returns to its root; this is the great outline of treatment."

Following these treatment principles, physicians through the dynasties have summarized, classified, and categorized TCM therapeutic methods to make them easier for later students to learn.

The most classic summary divides TCM therapeutic methods into eight: sweating (han), harmonizing (he), purging (xia), dissipating (xiao), vomiting (tu), clearing (qing), warming (wen), and supplementing (bu). This doctrine of the "eight methods of the medical school" was systematized by the Qing-dynasty physician Cheng Guopeng. He classified disease into the eight guiding principles of yin, yang, exterior, interior, deficiency, excess, cold, and heat (eight syndromes, or eight disease mechanisms), and applied corresponding neutralizing therapeutic methods to each. Because his doctrine was clear in its logic and easy to understand, it is now widely accepted.

Although Cheng Guopeng proposed the "eight methods of the medical school," he did not reduce TCM treatment to these eight rigid techniques; rather, he advocated flexible application. A single formula may employ several of the eight methods at once, for example combining the harmonizing, supplementing, and dissipating methods. He also held that any one method can be transformed into another, emphasizing that treatment must adapt to the clinical situation.

The sweating method, also called the exterior-resolving method, induces perspiration so that the pathogen that has invaded the body is expelled with the sweat. It mainly treats various exterior patterns and can relieve symptoms such as aversion to cold with fever, headache and body pain, nasal congestion, and discharge.

The harmonizing method, also called the reconciliation method, achieves the expulsion of pathogens and the regulation of zang-fu organ function through a mediating and harmonizing action. Its hallmark features are "the combined use of cold and heat, the combination of supplement and drain, and the simultaneous resolution of exterior and interior." Harmonizing formulas constitute the largest category in the TCM formulary and are commonly used for diseases of complex presentation.

The purging method, also called the downward-draining method, expels from the body food residue, retained fluids, blood stasis, and phlegm accumulation that cannot be normally discharged. It typically uses purgatives, blood-activating and stasis-resolving medicinals, or diuretics, and belongs in TCM to the aggressive downward-attacking method.

The dissipating method carries the meanings of dispersing, dissolving, and eliminating. Its targets overlap with those of the purging method, but its means differ. The dissipating method uses medicinals to gradually disperse accumulated food, stagnant qi, blood stasis, and phlegm congelation. It targets pathogens entrenched deep in the zang-fu organs that cannot readily be expelled by simple purging.

The vomiting method, also called the emetic method, uses medicinals or maneuvers to induce vomiting, bringing up pathogens lodged in the throat, chest, or epigastrium and relieving the patient. Western medicine also uses this approach to treat poisoning.

The clearing method, also called the heat-clearing method, clears warm-heat and fire-toxin pathogens through heat-clearing, fire-draining, detoxifying, and blood-cooling actions. The heat-clearing and detoxifying approach often mentioned by contemporary TCM physicians uses this method.

The warming method, also called the interior-warming method, expels interior-cold patterns through warming the interior and dispersing cold, and by restoring yang and unblocking the vessels. In modern times it is also called the yang-supporting method; its main indications are cold limbs, aversion to cold, pale complexion, absence of dry mouth, and a white tongue coating.

The supplementing method, also called the tonifying method, supplements the "insufficiency" of the body's yin, yang, qi, and blood. Its indications are deficiency patterns caused by any kind of "insufficiency" or "deficiency."

Contemporary TCM formula books, based on the above ideas, further divide TCM formulas into twenty categories for ease of learning and mastery: exterior-releasing formulas, purging formulas, harmonizing formulas, heat-clearing formulas, summerheat-resolving formulas, interior-warming formulas, exterior-interior jointly-resolving formulas, tonifying formulas, astringing and securing formulas, spirit-calming formulas, orifice-opening formulas, qi-regulating formulas, blood-regulating formulas, wind-treating formulas, dryness-treating formulas, dampness-disinhibiting formulas, phlegm-treating formulas, food-stasis-dispersing formulas, worm-expelling formulas, and emetic formulas.

But there is another school in TCM called the "classical formula school" (jing-fang pai), which disagrees with this classification. Its proponents argue that TCM formulas should not be rigidly categorized in this way; they advocate respecting history, especially the medical canons of the Han and Tang dynasties, and above all respecting the records in Zhang Zhongjing's Shanghan Lun (Treatise on Cold Damage) and Jingui Yaolue (Essentials of the Golden Cabinet). They would learn the use of TCM formulas according to the specific indications of each prescription.

For example, Guizhi Tang (Cinnamon Twig Decoction) is a famous formula in the Shanghan Lun and is in fact the very first formula listed there. Under the entry for Guizhi Tang in the Shanghan Lun appears the following passage:

"When taiyang contracts wind, the yang pulse is floating and the yin pulse is weak; floating yang means spontaneous heat, and a weak yin means spontaneous sweating. With astringent aversion to cold, shuddering aversion to wind, gentle and continuous fever, nasal snoring, and retching, Guizhi Tang governs. Guizhi Tang: Guizhi (cinnamon twig) three liang (peeled), Shaoyao (peony) three liang, Gancao (honey-fried licorice) two liang, Shengjiang (fresh ginger) three liang (sliced), Dazao (jujube) twelve pieces (broken). Crush the three of the five medicinals. With seven sheng of water, simmer over a gentle flame to three sheng, strain, and take at a suitable warm temperature, one sheng at a time. Shortly after taking it, drink a little over one sheng of hot thin congee to support the medicinal force. Wrap up warmly for about one shichen until a slight, mild all-over sweat is induced; it is best not to let the sweat pour out like flowing water, or the disease will surely not be removed. If, after one dose, sweating occurs and the disease resolves, stop; do not finish the rest of the package. If no sweat comes, take another dose as before. If still no sweat, shorten the interval and finish three doses within half a day. In severe cases, take it day and night and observe through a full twenty-four hours. If one package is finished and the disease pattern remains, prepare another. If no sweat comes, take two or three packages. Prohibit raw and cold, glutinous and slippery foods, meat and wheat products, the five pungent spices, wine and dairy, and rank, foul-smelling things."

This passage describes in detail the symptoms Guizhi Tang addresses—spontaneous sweating, aversion to cold, aversion to wind, fever, nasal snoring, and retching—and also explains in detail how to decoct and take Guizhi Tang and what dietary restrictions to observe. The classical formula school strictly follows the principle of "when this pattern is present, use this formula (or medicinal)."

This rigorous style of the classical formula school fits clinical practice well. But its somewhat rigid flaw is that it overemphasizes the role of the Shanghan Lun and Jingui Yaolue; its adherents maintain that all diseases can be solved with these classical (time-honored) formulas. Gradually, an approach that originally fit clinical reality developed into a dogma, and thereby detached itself from clinical reality once more.

In practice, the symptoms of most chronic-disease patients are highly complex; patients do not fall ill according to the textbook, and a physician treating disease cannot mechanically apply these classical formulas.

I myself lean toward the more moderate "formula-pattern school" (fang-zheng xuepai). It likewise follows the principle of "when this pattern is present, use this formula (or medicinal)," but the range of formulas it draws on differs. Outstanding formulas from all dynasties, and even effective formulas and medicinals screened out in modern controlled trials, can all be incorporated into the formula-pattern system.

Nor do I reject the TCM eight methods or the modern TCM summaries and classifications of formulas, because those, too, are built on clinical efficacy.

In the end, whatever the school of TCM, the root idea of treating disease remains "reduce what is in excess, supplement what is insufficient"—adjusting the body's states of "too much" and "too little."

Once the principle and method are established, the clinician's approach to composing a formula is fixed. The next step is choosing the formula and the medicinals; above all, the chosen formula and medicinals must relieve the patient's corresponding symptoms. This is where a physician's foundational skill is tested. In my view, the most solid foundation in TCM lies in memorizing the indications of formulas and medicinals, for that best ensures that a TCM prescription actually works.