Chinese Herbal Medicine is a branch of Traditional Chinese Medicine, using the same theoretical basis as Acupuncture. The roots of Traditional Chinese Medicine reach far back into antiquity since the original systematic exposition of its principles and practice are laid out in the 1st Century AD text, the Nei Jing or Inner Classic. Although this purports to be a conversation between the mythical Yellow Emperor and his minister Qi Bo, it is in fact the foundation stone of Chinese Medicine, articulated, developed and corrected over the following millennia. It established the foundations of a naturalistic medicine, with a complete physiology of bodily processes, theories about the origins of illness and comprehensive procedures for treating illness. Although the Nei Jing concentrates on acupuncture protocols, the qualities of medicinal substances and a limited number of herbal prescriptions are discussed.
To talk about the ancient roots of Traditional Chinese Medicine (TCM) is to do more than to claim its antiquity as justification for its existence. It is to point out that the theories and clinical practice of Chinese Herbal Medicine stretch back in a way that allowed following generations to authenticate and to develop the written works of their ancestors. When circumstances changed, as when epidemics of febrile disease swept through the newly city-based populations in the 16th Century and it was found that the older theories and prescriptions were not effective for new diseases, different theories and prescriptions had to be developed. However, unlike in the West where the medieval theory of the humours were abandoned with the rediscovery of Greek and Roman knowledge and the advent of modern rationalism, the history of Chinese Medicine is that of the retention of clinically effective knowledge and practice. Hence those prescriptions first formulated for viral and bacterial diseases in the 1st Century AD Treatise on Diseases caused by Cold continue to be used side by side in the clinic with those formulated in the 18th Century for viral and bacterial diseases of a febrile nature.
The first written Materia Medica, the 1st Cent. BC Shen Nong Ben Cao systematises the medicinal substances used in Chinese Herbal Medicine. It lists 365 substances, of which 246 are plants. The high point of classical herbals is the 16th Century Ben Cao Gang Mu of Li Shi Zhen, a contemporary of Gerard. This contains 1890 medicinal substances, of which 800 are plants, arranged in groupings with an obvious similarity to the family and genera recognised by botanists today.
The Shen Nong Ben Cao divided medicinal substances into three classes. The first are those which are Superior, have no toxicity, can be taken frequently over a long period without injuring and which ‘lighten the body, benefit and Qi and retard ageing’. Middle or mediocre substances are those which can ‘retard and repair enfeeblement and emaciation’. Lower, or Inferior, substances are those which should not be taken long term and which are used ‘to break down accumulation and masses and to bring about recovery from illness’.
What becomes clear is that the concept of Inferior means that the practice of herbal medicine, just like allopathic medicine, includes the use of substances which are to be avoided unless absolutely necessary and to be discontinued once they have done their work. These are not toxic in the sense of poisonous, but are described as having certain properties which are not desirable in the long term. Correct prescription, correct dosage, and a balanced herbal formula (or chosen selection of herbal substances) is all crucial in determining whether or not the use of a herb will be balanced in its use.
It is important to stress that this historical aspect of CHM is not simply academic but was important for clinicians seeking clarification of clinical application. In 1757 a writer on CHM said as follows: ‘All substances which have strong Qi (ie nature or properties), and which are very powerful are one-sided. In consequent of being one-sided, they have advantages but can necessarily also be injurious. It is desirable that the benefits be selected and that the injurious properties be eliminated, so the method of use entails certain preparation to render the one sidedness more gentle. The principle of these preparations is different in each case’. (Xu Da-Chun, 1757)
This is a reference to another aspect of clinical practice or Pao Zhi , whereby the properties of a medicinal substance are altered so as to mitigate any possible negative effects. So, for instance, the use of raw Da Huang, (Radix et Rhixoma Rhei), a Shen Nong Inferior Herb, is appropriate for certain clinical situations where purging is necessary and possible. However, by stir frying it or by soaking it in wine, its properties are altered so that instead of being cold, bitter and purging, it becomes warm, pungent and ascending in nature and suitable for patients who could not tolerate its raw character.
Similarly, each practitioner learns the art of Dui Yao, the art of established combinations of medicinals which work particularly well either to augment each others effects or to mitigate the to mitigate possible harsh effects of medicinal substances. Untreated Ma Huang, or Ephredra, is completely different in its action from honey treated Ma Huang. The first will be used to make a patient lightly sweat or to relieve wheezing. The second is used where the patient is considered too weak for the properties of the untreated herb, but needs a modified gentler version of its actions.
The first prescription books, the ‘Shan Han Lun’, on external diseases and the ‘Essentials from the Golden Cabinet’ on internal medicine dates from the later Han or 3rd C AD. One fifth of the formulae in the modern standard formula textbook, ‘Formulas and Strategies’ originates with these texts. Like the Nei Jing, they are the foundation texts for the practice of Chinese Herbal Medicine. So they form the beginning of the creation of a vast range of clinically effective formulae, examined and augmented by generations of scholars and clinicians over the following millennia. These formulae set the parameters for the effective practice of CHM. Herbal formulae are carefully selected combinations of medicinal substances. They are designed to address the main complaint and other possible symptoms of the patient in as compact a form as possible.
So it is that any practitioner of CHM has to have a thorough knowledge both of the individual substances used and of the blueprint formulae, the combinations of medicinal substances found through clinical practice to be most effective for certain clinical situations. Effective and skilful practice of CHM entails the tailoring of the blueprint formulae to the individual condition of each patient and the adaptation, sometimes daily, of the formula to the changing circumstances of his/her illness.
The process of diagnosis in TCM is to establish which medicinal substances, in which most appropriate combination, best fits the situation of the patient presenting. In this respect CHM shares its practice with other herbal traditions. However, the process of diagnosis in CHM is that whatever the complaint, be it a symptom such as insomnia or a biomedical disease such as diabetes mellitus, is always differentiated by the practitioner in terms of the physiology and diseases processes of Chinese Medicine.
This is explained by the Chinese expression, ‘One disease, Many Causes’. In TCM, a pattern of seemingly disparate symptoms will point to a clinically established pattern of disharmony of the body’s processes. Similarly, although patients may share an established biomedical diagnosis, the process of diagnosis is that of differentiating the particular symptoms and signs of that patient into the individual ways that patient expresses their illness. So, to give a simple example, insomnia characterised by palpitations, vivid dreams, night sweats, a dry red tongue body and weak thready pulse will require a completely different approach and very different herbs from insomnia where the patient experiences extreme irritability, headaches, bitter taste, constant heat, nightmares, a red tongue with yellow coating and a full strong pulse.
Those of us who have had the opportunity to observe herbal practice in China saw patients come into the clinic with their medical notes in their hands. These notes contained all the information about standard medical tests. The practice of the doctor was to use the information provided by the tests to fine tune the selection of the herbs appropriate for that patient and incorporate them into their formulae.
The skilful practice of CHM therefore now means that the creation or adaptation of the formulae will be informed by recent research on the properties of the medicinal substances. This means that a formula for diabetes mellitus will not only answer as fully as possible the patterns of disharmony as established by CHM but will also include the most appropriate choice for that particular patient of those substances shown to have a hypoglycaemic effect. This is the most effective synthesis of ancient experience and modern research.
