Pulse diagnosis and reading form an integral part of the TCM consultation process, facilitating diagnosis and informing herbal formulations.
Now that consultations with Western doctors are often brief, one of the strengths of traditional Chinese medicine (TCM) is the emphasis put on a thorough process of verbal inquiry. Occasionally, that which has been overlooked in a patient’s conventional medical journey can be discovered by purely taking the time to ask questions and listen to the responses.
However, the insight into the body afforded to Western medicine by modern imaging, haematology and biochemical investigations, TCM has lacked in its historical development. Although such diagnostic tests have some role in modern TCM diagnosis today, historically, the direct route to understanding what was happening internally was by feeling the pulse at the radial artery and looking at the tongue. To a lesser extent, other non-verbal examinations included listening to breath sounds and the smelling of characteristic odours. Taken together, inquiry, observation, palpation, as well as listening and smelling (taken as one category) constitute the four diagnostic methods of TCM.
The historical interpretation of the radial pulse
Although tongue diagnosis gained prominence in the later history of TCM, during theMing (1368–1644) and Qing (1644–1912) dynasties, the greatest emphasis has traditionally been on diagnosing through reading the pulse. The earliest mentions of pulse diagnosis are found in the Huangdi Neijing (Yellow Emperor’s Inner Canon), a foundational TCM text dating to around 200 BCE (1). The text describes the pulse as a reflection of qi, blood, and organ function. It established the idea that different parts of the body’s condition could be assessed through palpating the radial pulse.
Wang Shuhe [180–270], a prominent physician of the Jin dynasty, compiled the Mai Jing (Pulse Classic), which remains a cornerstone text on pulse diagnosis (2). The Mai Jing systematically described the locations, methods, and classifications of pulse qualities, of which it distinguished 24, such as full, scattered, deep, and firm. The radial artery on each wrist was divided into three sections and two depths, each reflecting the condition of specific organs. Hence, the 12 pulse positions were thought to represent the 12 organs of Chinese medicine physiology.
Such exact correspondences are rather characteristic of the formation of Chinese medical theory and usually became compromised by historical and practical developments. In the case of pulse diagnosis, the most influential modification was a multi-author text, the Bin Hu Mai Xue (The Lakeside Master’s Study of the Pulse), edited by its final author, Li Shi Zhen, in 1564 (3). Li ShiZhen, who was also the compiler of one of the most important materia medica, the Bencao gangmu (Compendium of Materia Medica) (4), adjusted some of the correspondences of the pulse positions, such that the distal position on both arteries represented the upper part of the body and its organs, and, the middle and proximal represented the middle and lower parts of the body. He also increased the number of pulse qualities to 27, just short of the 28 which are currently found in modern textbooks.
The primacy of pulse qualities
In modern clinical practice, the pulse is given varying significance, largely dependent on individual practitioners. Although, as a generalisation, acupuncturists often pay more attention to the correspondence of pulse positions, whilst herbalists will ignore these or greatly simplify them in favour of an emphasis on the overriding pulse quality.
It must be said that many herbal case histories from China or, indeed, the West make no mention of pulse position. The ambiguous situation has been tactfully expressed in a well-regarded modern Chinese diagnostic text where the author states that in the face of centuries of historical use, the attribution of the six pulses (three on each wrist) “ought not to be easily agreed with nor disagreed with” (5). In my practice for instance, although I may be impressed by a pulse which is felt strongly distally but not proximally, or vice versa, it is the quality of the pulse which guides diagnosis and herbal prescribing.
A consideration of pulse qualities was, up until the early 20th century, not unique to Chinese medicine; William Osler’s The Principles and Practice of Medicine, published in 1892, included detailed descriptions of pulse characteristics such as amplitude, speed, rhythm and force (6). Whilst, in Western medicine, this knowledge has given way to other diagnostic tests, in Chinese medicine the 28 pulse qualities are still applied.
The problem with learning the 28 qualities is that when presented in its full range, and with some of the terminology such as scattered, onion stalk, and soggy, they can appear complicated and mysterious. However, the descriptions, developed over a written history of 2000 years, embody a great strength of Chinese medicine, that of reflecting the practitioner’s fundamental observations. By grouping the pulses, including the more obscure sounding ones, into their most basic categories they can be seen to have a direct resonance with our patients’ being and subsequent treatment. As such, pulse diagnosis reflects a key holistic method.
The basis of pulse diagnosis
The most famous concept of Chinese medicine is that of yin and yang, which is applied to inform the diagnosis of a condition, and then to the differentiation of the herbs used in a prescription. However, this dichotomy informs the basis of deficiency and excess cold and hot; interior and exterior.. These six dichotomies, along with the overarching concepts of yin (too little, cold, interior) and yang (too much, hot and outside) comprise the basis of diagnosis called the eight principles.
All of the 28 pulse qualities fall under these fundamental diagnostic distinctions: a strong pulse indicates a pathogen excess, whilst a weak pulse indicates a lack of physiological substance. A rapid pulse indicates an excess of heat, whilst a slow pulse indicates cold. A floating pulse indicates the recent arrival of the disease to the exterior, or that the qi is directing outward.
Whilst, finally, a deep pulse indicates the disease is in the interior. Herbal treatments are thus prescribed according to these distinctions. Therefore, where the pulse shows signs of an excess of a pathogenic substance, the practitioner will want to use herbs which reduce it by various means. In cases of a weak pulse, the practitioner will seek to supplement or tonify, with cooling or warming herbs, also treating either the exterior or interior.
In current modern practice, feeling the pulse is only one of the diagnostic inputs, and some of these might provide contradictory findings or indicate different locations of disease. The skill and experience of the practitioner is involved in identifying the central issues and this involves applying further theory about fundamental mechanisms.
Pulse qualities and some indicated herbs
A full or excess pulse is firm and forceful at all levels. It can indicate a healthy individual but in disease, it indicates an excess of a pathogen. In a combination of qualities, if a pulse is full and slow, it indicates an excess of cold, or, if it is full and rapid an excess of heat. In the former case, the herbalist might prescribe a heating herb like gan jiang (Zingiber officinale | ginger) which warms the Stomach and Spleen. In the latter case, a more cooling herb like huang lian (Coptis chinensis | Chinese goldthread) would be considered as it clears heat from the Heart and Stomach. In an extreme case, huang lian could be combined with da huang (Rheum palmatum | rhubarb) to purge heat through the bowel.
Variants of a full pulse include the slippery pulse, which is said to be smooth and flowing and indicates an accumulation of phlegm or dampness and, in health, pregnancy. A primary herb for clearing phlegm is ban xia (Pinellia ternata | crow dipper) and this is often used with chen pi (Citri reticulatae | dried tangerine peel).
A full pulse whose forcefulness is expressed through having a very clear definition of its edges is designated as wiry, and described as being like the string of a musical instrument. This pulse indicates that qi has accumulated and, although qi is a physiological substance, it has now become pathogenic in its effect. The accumulation of qi is associated with symptoms caused by the movement of qi to areas where it doesn’t usually reside. These can be physical, like headaches, or emotional, like anger and other stress responses. This is often regarded as a Liver or Gallbladder (in the Chinese sense of these organs) disharmony.
The key herb for such patterns is chai hu, (Bupleurum chinense | chai hu) as well as the core formula on which many others are based: Si Ni San (Four Extremities Powder). This is comprised of chai hu and zhi shi (Aurantii immaturus | bitter orange), which both move the qi, along with bai shao (Paeoniae alba | white peony) and gan cao (Glycyrrhiza glabra | liquorice) which both soothe and harmonise the qi. The formula is so named because when qi is blocked it does not flow to the extremities, which are then often cold despite the body’s core being warm.
A weak or empty pulse is forceless and soft on all levels. It indicates a lack of qi and blood and, if only felt deeply, a lack of yang qi. Variants include the soggy pulse which is weak and floating and indicates a lack of qi accompanied by dampness, and the thready or fine pulse which especially indicates a lack of blood. Key herbs which might be indicated for such patterns include ren shen (Panax ginseng | panax), which strongly supplements the qi, and bai zhu (Atractylodes macrocephala | bai zhu), and fu ling (Poria cocos | poria) which more gently supplements the qi but also removes dampness.
Herbs which supplement the blood include shu di huang (prepared Rehmannia gluttinosa | rehmannia) and dang gui (Angelica sinensis | Chinese angelicai). The generic formula which combines herbs to supplement the qi and blood, and indicated for those with a pulse which is weak and thready, is Ba Zhen Tang, (Eight Precious Decoction). This is composed of ren shen , bai zhu, fu ling, zhi gan cao, shu di huang, dang gui, bai shao, and chuan xiong (Ligusticum chuanxiong | Sichuan lovage root).
Conclusion
The pulse categories of slow, rapid, floating and sunken similarly have a number of variations to account for all the 28 qualities. Each quality points toward key herbs and formulas although, of course, in the end this only forms part of a whole picture. Pulse diagnosis provides part of a pathway through the confounding problem with a holistic diagnosis, which is that there are often many diagnostic signs indicating an unfeasibly large array of indicated herbal treatments. Through assessing the pulse, it provides a foundation for building a picture of the core disharmony.
References
- Unschuld, P.U., Tessenow, H. and Zheng, J. (2011) Huang Di Nei Jing Su Wen: An annotated translation of Huang Di’s inner classic – basic questions, 2 volumes, volumes of the Huang Di Nei Jing Su Wen Project. Berkeley: University of California Press.
- Two historical accounts of Chinese pulse diagnosis which include mention of the Mai Jing are: Flaws, B. (2012) The Secret of Chinese Pulse Diagnosis. Boulder, CO: Blue Poppy Press; and Buck, C. (2015) Acupuncture and Chinese Medicine: Roots of Modern Practice. London: Singing Dragon.
- Li, S. and Flaws, B. (2002) The Lakeside Masters’ Study of the Pulse, Bin Hu Mai Xue. Boulder, Colo: Blue Poppy Press.
- Unschuld, P.U., Tessenow, H. and Zheng, J. (2011) Huang Di Nei Jing Su Wen: An annotated translation of Huang Di’s inner classic – basic questions, 2 volumes, volumes of the Huang Di Nei Jing Su Wen Project. Berkeley: University of California Press.
- Deng, T. (1999) Practical Diagnosis in Traditional Chinese Medicine. Edited by K. Ergil. Edinburgh: Churchill Livingstone.
- Osler, W. (1892) The Principles and Practice of Medicine . London: Young J. Pentland.
