TCM as a Style
The hallmark of TCM as a style of Chinese medicine is its emphasis on treatment based on pattern discrimination (bian zheng lun zhi). This means that, although TCM practitioners first make a disease diagnosis (bian bing), treatment is based more on the pattern discrimination than on that disease diagnosis. In other words, the overall guiding treatment principles for the case at hand are based on the pattern discrimination, not on the disease diagnosis. It is these principles which guide the selection of the Chinese medicinal formula or main acupuncture points. Once these main principles are stated and a basic treatment protocol is erected based on these principles, medicinals or acupuncture points are then added to the base protocol depending on their empirical efficacy for the particular disease under treatment.

For instance, a patient may be suffering from headache. In TCM, headache (tou tong) is a disease category. If the patient also says that her headache comes at the end of every menstruation, is worse at night or when fatigued, tends to be generalized, typically lasts until she goes to bed but is usually gone when she wakes the next morning, and if her facial complexion is a sallow yellow, she has palpitations or dizziness, lack of warmth in her four limbs, a scanty appetite, loose stools with her period, pale nails, a pale tongue, and a fine and weak or relaxed pulse, her TCM pattern discrimination is one of blood vacuity due to spleen vacuity. In that case, the main treatment principles are to fortify the spleen and nourish the blood. The guiding formula in that case might be either Ba Zhen Tang (Eight Pearls Decoction) or Gui Pi Tang (Restore the Spleen Decoction) depending upon the exact signs and symptoms. If Gui Pi Tang were chosen, then Radix Ligustici Wallichii (Chuan Xiong) might be added to specifically upbear blood to nourish the sea of marrow and therefore address the specific complaint of headache.

If treated by acupuncture, the basic formula might consist of Zu San Li (St 36), San Yin Jiao (Sp 6), Pi Shu (Bl 20), and Ge Shu (Bl 17). The first three points all fortify the spleen, remembering that it is the spleen which is the root of latter heaven or postnatal qi and blood engenderment and transformation. Ge Shu is the hui or so-called reunion point of the blood. It specifically acts to nourish the blood. If the major complaint or disease were palpitations, then Shen Men (Ht 7) might be added to this basic formula. However, because the disease under treatment is headache, Bai Hui (GV 20) might be added with moxibustion in order to upbear yang qi, based on the premise that it is the qi which moves the blood and that the blood follows the qi.

It is said in TCM:

Yi bing tong zhi
Tong bing yi zhi
One disease, different treatments;
Different diseases, one treatment.

This means that any disease may present a number of different patterns. In the case of headache, there are wind cold external invasion pattern headaches, liver yang hyperactive above pattern headaches, phlegm dampness obstructing the clear portals pattern headaches, blood vacuity pattern headaches, and essence insufficiency pattern headaches, to name the most common ones. Although two patients may each suffer from headache, if their TCM pattern discrimination is different, they will receive a different treatment. Another two patients may present with two completely different diseases. One may be suffering from headache and the other from insomnia and yet, as long as they present the same overall TCM pattern, their treatment may be essentially the same.

Therefore, in TCM, a correct pattern discrimination is vitally important. It is the guide and foundation to successful, individualized treatment. When treatment is given on the basis of a correct TCM pattern discrimination, it restores balance without iatrogenesis or side effects. In addition, a TCM pattern discrimination contains within itself an explanation of why the person is manifesting the signs and symptoms they do. Each pattern is the result of certain disease causes (bing yin) and disease mechanisms (bing ji). If one understands those disease causes and mechanisms, then one can take steps to alter or abolish them. One can change their diet and lifestyle accordingly and even change deleterious mental/emotional habits. Thus a TCM pattern discrimination is both enlightening and empowering in a way that a simple disease diagnosis typically is not. Hence, TCM pattern discriminations are the means by which practitioners of Chinese medicine can follow the injunctions in the Nei Jing (Inner Classic) to emphasize prevention over mere remedial treatment.

How Patterns Are Discriminated
TCM patterns are discriminated by means of the four examinations (si zhen). These are visual examination (wang zhen), inquiry (wen zhen), listening and smelling examination (wen zhen), and palpation (qie zhen). It is by means of the combination of these four methods of examination (si zhen he can) that a TCM pattern is identified. However, most modern TCM clinical manuals describe this combined summation and analysis in terms of main symptoms (zhu zheng), examination of the tongue (she zhen), and pulse examination (mai zhen). In other words, in clinical practice, patterns are based on three broad groups of information: 1) signs and symptoms, 2) tongue examination, and 3) pulse examination. It is the comparison and corroboration of these three groups of information which differentiate one pattern from another, and it is extremely important that no one sign or symptom means anything except in relationship to all other signs and symptoms gathered by the four examinations.

For instance, the pattern of spleen qi vacuity and spleen yang vacuity have many of the same signs and symptoms. In both patterns there are scanty appetite, loose stools, abdominal distention, fatigue, lack of strength, and a pale tongue with a thin, white coating. However, in the case of spleen yang vacuity there are also chilling of the limbs, a cold body, and a slow pulse. But this does not mean that chilled limbs are always a symptom of yang vacuity. There may be chilled limbs due to liver depression/qi stagnation. In this case, the four chilled limbs are referred to as the four counterflows because yang qi is depressed internally and cannot flow uninhibitedly out to the extremities. One knows this because the tongue in this case is a dark reddish and may have a yellowish coating, while the pulse is wiry and rapid, not slow.

Thus it is vitally important to keep in mind that no one sign or symptom always means any one thing. It only means something when taken in consideration of all other signs and symptoms, including the tongue and pulse examinations.

The TCM Methodology
This basic TCM methodology of moving from a major complaint to the patient's individual signs and symptoms, tongue, and pulse, thus constituting the pattern discrimination, thence to the statement of treatment principles, and only then to the selection of a guiding formula or protocol and its individualized modifications is exemplified in the organization of most modern Chinese TCM clinical manuals. In such clinical handbooks, information is typically given under the following headings and in the following order:

Disease name:

Treatment based on pattern discrimination:

Pattern name:

Main symptoms:

Tongue & coating:

Pulse images:

Treatment principles:

Formula:

Additions & subtractions based on symptoms:

Just as most Chinese clinical manuals and textbooks are organized in this manner, it is important that clinicians follow this methodology or progression when making a pattern discrimination and then erecting a treatment plan. This is a very step by step methodology, and if one omits a step, then the whole process may go awry. It is especially important to write down the TCM pattern discrimination and the treatment principles before writing down the names of Chinese medicinal formulas or acupuncture points. I have explained this process at greater length in both my Sticking to the Point: A Rational Methodology for the Step by Step Formulation & Administration of a TCM Acupuncture Treatment and How to Write a TCM Herbal Formula.

The Importance of Pulse Examination
As seen above, pulse examination is one of the main methods of establishing a TCM pattern discrimination. Pulse examination in modern TCM primarily means the feeling of the pulse of the radial arteries at the styloid processes of both wrists. This is commonly called the cun kou or inch opening. It is believed by practitioners of Chinese medicine that the pulses felt here can be read as a simulacrum of the flow of qi, blood, and body fluids of the entire body. The first chapter of the Nan Jing (Classic of Difficulties) opens with the following question:

All the twelve channels have [sections where the] movement [in these] vessels [can be felt]. Still, one selects only the cun kou in order to determine whether the five viscera and six bowels [harbor a] pattern of death or life, of good or evil auspices. What does that mean?¹

The answer of why one can determine the health and disease of the entire body by feeling the pulses at the cun kou on the wrists that the Nan Jing gives is this:

The cun kou constitutes the great meeting point of the [contents passing through] the vessels. It is the [section of] the hand tai yin [channel where the] movement [in that] vessel [can be felt]. When a [normal] person exhales once, [the contents of] the vessels proceed 3 inches. When [a normal person] inhales once, [the contents of] the vessels proceed [another] 3 inches. Exhaling and inhaling [constitute one] breathing [period]. During this period, [the contents of] the vessels proceed 6 inches. A person, in the course of one day and one night, breathes altogether 13,500 times. [During that time, the contents of] the vessels proceed through 50 passages. [That is,] they circulate through the body [in the period needed by] the [clepsydra's] dripping water to move down by 100 markings. The constructive and defensive [qi] proceed through 25 passages [during a] yang [period], and they proceed through 25 passages [during a] yin [period]. This constitutes one cycle. Because [the contents of the vessels] meet again, after 50 passages, with the cun kou, [this section] is the beginning and the end of [movement of the contents of the vessels through the body's] five viscera and six bowels. Hence, the pattern [of death or life, good or evil auspices harbored by the body's five viscera and six bowels] may be obtained from the cun kou.²

Whether or how one chooses to accept this explanation aside, it is a fact that practitioners of Chinese medicine have been diagnosing and treating patients on the basis of pulse examination carried out at the inch opening for at least 2000 years. On the other hand, most Western students of TCM find pulse examination very confusing and difficult to master. It seems somehow very mystical and arcane. Although most Western practitioners express a strong belief and interest in pulse examination, few, I think, feel very confident of their abilities in this domain.

This Western ambivalence toward and pervasive lack of mastery of pulse examination is, I believe, exacerbated by a somewhat similar attitude toward pulse examination current in the Peoples' Republic of China at least in the 1980s. When I was a student in China during that time, the importance of pulse examination was deliberately played down by many of my teachers and clinical preceptors. Based on conversations, it seems they felt that pulse examination was hard to validate by Western anatomy and physiology and, therefore, was a bit of an embarrassment to people who were desperately trying to become modern and scientific. At that time, I never had a teacher tell me a pulse was anything other than wiry, slippery, fast, slow, floating, deep, or fine. One of my teachers only took the pulse with two fingers and never expressed her readings in terms of the three basic positions of the pulse. When queried about this, she said that it is scientifically impossible for the pulse to have different qualities or images in different positions. Ergo, one does not have to worry about positions.