The Key to Learning TCM Is Mastering Formula-Pattern and Herb-Pattern Correspondence
How can the clinical cure rate of TCM be raised? Although opinions differ, one point is commonly esteemed: the importance of TCM pattern differentiation and treatment (bianzheng lunzhi).
But when it comes to pattern differentiation, the TCM world has had many disputes since ancient times, and no unified view has yet been formed. One main reason is that most TCM physicians hope TCM will not remain simply at the level of empirical medicine, but try to elevate it into a pattern-differentiation thinking that can guide clinical practice with a highly generalized medical principle. Yet this "elevation" must be undertaken with extreme caution; if it is built on wishful thinking, then guiding clinical practice according to the elevated theory will produce errors everywhere.
Thus the various TCM pattern-differentiation systems—eight-principle pattern differentiation, six-meridian pattern differentiation, zang-fu pattern differentiation, triple-burner pattern differentiation, and construction-defense and qi-blood pattern differentiation—all have their share of controversy.
Take the six-meridian pattern differentiation in the Shanghan Lun: some say it differentiates according to the channel and collateral theory, while others hold that the six meridians in the Shanghan Lun are different from those in the Huangdi Neijing, and that the six meridians here are merely a name unrelated to specific channels.
Professor Hu Xishu was deeply influenced by Japanese kampo physicians such as Yoshimasu Noriyoshi (Ji Yi Wei Ze) and Tang Ben Zhen Qiu, and he interpreted the six meridians of six-meridian pattern differentiation using the eight-principle theory. He held that taiyang disease is an exterior yang pattern, shaoyin disease an exterior yin pattern, yangming disease an interior yang pattern, taiyin disease an interior yin pattern, shaoyang disease a half-exterior-half-interior yang pattern, and jueyin disease a half-exterior-half-interior yin pattern.
Hu's descriptions of the exterior, interior, and half-exterior-half-interior patterns basically reproduce the original text of Tang Ben Zhen Qiu. Tang Ben Zhen Qiu held that the exterior refers to the surface tissues such as the skin, the interior to the digestive organs, and the half-exterior-half-interior to the organs in the thoracic and abdominal cavities other than the digestive organs; Professor Hu Xishu defined the exterior, interior, and half-exterior-half-interior patterns in the same way. Tang Ben Zhen Qiu inherited Yoshimasu Noriyoshi's doctrine that "all diseases arise from a single toxin," proposing that human illness is mostly caused by water toxin, food toxin, and blood toxin; this view was basically reproduced verbatim in the only paper Professor Hu wrote in his lifetime.
Professor Hu Xishu once overturned all the mysterious, speculative interpretations the ancients had placed on the Shanghan Lun, restoring TCM classical-formula medicine to a pattern-differentiation and treatment medicine centered on formula-pattern and herb-pattern. Moreover, Professor Hu was one of the old physicians with the most outstanding clinical efficacy at Beijing University of Chinese Medicine, so his views are very persuasive. He valued evidence and treated all speculative, mysterious talk cautiously—a great step forward.
But Hu's theory cannot be called perfect. Is the eight-principle pattern differentiation he still upheld very reliable? Does his redefinition of the six meridians and his delineation of the exterior, interior, and half-exterior-half-interior patterns correspond to reality? That is not certain either. For example, many formulas that treat interior patterns may also work well for what Hu called exterior and half-exterior-half-interior patterns. The exterior, interior, and half-exterior-half-interior patterns do not fully correspond to Tang Ben Zhen Qiu's descriptions.
The core of so-called pattern differentiation and treatment is "for this pattern, use this medicine"; in today's language, whatever prescription or medication indications the patient presents is the formula or drug one selects. This symptomatic method is the simplest, most objective, and possibly the most effective approach. Professor Hu Xishu said that the formula-pattern is the cutting edge of pattern differentiation and treatment. Although he himself creatively transformed six-meridian pattern differentiation into eight-principle pattern differentiation, he also acknowledged that the careful study of specific formula-patterns was the key to his clinical results.
According to Hu's students, when writing prescriptions he often described the patient's condition in terms of "Guizhi Decoction pattern," "Kudzu Decoction pattern," or "Minor Bupleurum Decoction plus Gypsum pattern." The key points of Hu's differentiation were to collect evidence such as the patient's clinical symptoms, tongue appearance, and pulse, then judge which classical formula the patient's series of symptoms best corresponded to, and determine that the patient belonged to a certain formula-pattern.
Unlike most TCM doctors, Hu would not use vague terms such as "kidney yin deficiency," "liver yin deficiency," or "non-communication between heart and kidney," but carefully identified which formula-pattern the patient belonged to. For example, if a patient sweats easily, fears cold, fears wind, and has stiff pain in the head and neck, this series of symptoms is precisely the indication for Cinnamon Twig Decoction (Guizhi Tang); Hu would say the patient belongs to the Guizhi Tang pattern, rather than giving a vague diagnosis such as yang deficiency or qi deficiency. In that case, prescribing Guizhi Tang directly achieves symptomatic treatment, and the effect is often immediate.
For a thousand years, debate over TCM pattern-differentiation thinking has never ceased, but debate over TCM formula-pattern and herb-pattern has been rare. A TCM physician who falls into the labyrinth of purely theoretical pattern differentiation may ultimately harm both others and himself. Professor Liu Fangbo believes that if a TCM physician concentrates on learning formula-pattern and herb-pattern, he can become an effective clinician in the shortest time; this is the shortcut to learning TCM. I agree with him. I believe that TCM pattern-differentiation thinking—whether eight-principle, six-meridian, or triple-burner differentiation—is all vague, whereas formula-pattern and herb-pattern are objective and clear, independent of any doctor's subjective consciousness.
Medication indications and formula indications are the experience derived from countless doctors' and patients' clinical practice; this experience is the most reliable, so it should be the true essence of TCM. Moreover, formula-pattern and herb-pattern best conform to the spirit of evidence-based medicine. When we treat patients, if there are very sufficient and reliable medication indications, it is easy to obtain definite efficacy. If there are no obvious formula or medication indications, the clinical effect will not be so certain.
Wang Haogu held that a physician must first know disease and second know drugs; therefore, what clinicians should most diligently study are the clinical features of diseases and the indications of formulas and drugs. The ideal state is to find the most accurate correspondence between disease and drug. Disease and drug are the relationship between lock and key: find the right key and the lock opens; find the wrong key and, despite expending all one's strength, the lock will not open.
After studying TCM long enough, we realize that although TCM classics fill warehouses, the truly valuable words within them are not many. When I first read TCM classics, I often read them reverently, word for word. By now I know that much speculative text should be skipped so as not to waste time and mislead myself. Precious time should be spent learning the features of diseases, the effects of drugs, and the medication indications of formulas. Master these three, and clinical treatment has an objective and reliable guide, without relying on subjective guessing of the "the physician's mind" kind.
In a thick medical work, the truly valuable content may be only a few thin pages. As the ancients said: truth is half a sheet of paper; idle talk fills ten thousand books. TCM theory has been constructed by so many people across the ages that to part the clouds and sift gold from the sand, learning what is truly valuable from TCM books, is no easy task.