Acupuncture involves the insertion of very fine needles at specific points in the body. This rather strange practice was uniquely developed in China about 2000 years ago, and all present-day schools of acupuncture (and there are many), trace their development directly from this historic instance. Many of the other treatment modalities practiced under the broad umbrella known as Traditional Chinese Medicine (TCM), such as herbalism (in the broad sense, referring to any set of substances considered to have medicinal effects, whether of vegetable origin or not), massage, surgery, bonesetting, various forms of lancing and bloodletting, and lifestyle and dietary modification, have also arisen independently in many other times and places in human history. But acupuncture appears to have been discovered/invented only once.
According to currently available historical and archaeological sources, acupuncture seems to have arisen within a relatively short time during a period of intellectual ferment and medical innovation in China. Many strands of what is now collectively known as Traditional Chinese Medicine (TCM) were already documented in some of the earliest extant Chinese writings, precisely dated to pre-168 BCE, whereas the technique of acupuncture, completely absent in these early writings, appears almost fully fledged in the Huang Di Nei Jing Ling Shu, parts of which have been dated, using textual criticism methods, to early in the first century CE.
This was a time when various schools of thought, including the Daoist and Confucian schools, began to look for natural explanations for physical phenomena, including the normal functions of the human body and its diseases. Cultural theories of disease at this time included the actions of supernatural agents with evil intentions, such as evil spirits, hungry ghosts, or insufficiently venerated ancestors. Scholars in the various schools of thought, especially the Confucianists, countered with explanations that remained within the bounds of the observable processes and phenomena of the natural/physical world – the change of the seasons, the transformation of night into day, and vice versa, the natural course of development of the human being from birth to death with both its normal (physiological) changes appropriate to each stage, and its abnormal (pathological) changes which signal disease. Those who wrote works that have survived in the classical TCM canon, were active and experienced clinicians with a facility for observation, and even more importantly, for recording their observations.
These thinkers, dispensing entirely with supernatural explanations for disease, proposed several new, natural disease mechanisms: including, for example, the environmental (external) and the emotional (internal). The environmenal causes refer to the idea that different climate factors can invade the body from the outside and cause disease – wind, cold, heat, dampness, etc. Such external causes were certainly linked with what are now understood to be infectious diseases, caused, in accordance with modern research, by invasions of viruses or bacteria – for example, colds, flus, measles, etc – but also with other diseases/conditions for which current research has found no infectious agents – for example, rheumatoid arthritis, or some types of dysmenorrhea (painful periods).
Naturally, there is nothing in our current understanding of physiology which can make sense of such concepts as being invaded by wind, or retaining dampness, if they are taken in a strictly literal sense. Nevertheless, such concepts continue to be used by thousands of TCM practitioners both inside and outside of China, because when they were initially developed they were directly linked to clinically observable disease states and such disease states have not changed very much in the intervening period. Such descriptions also still link well-described disease states to treatments that continue to be empirically useful and effective.
The traditional theory which underpins acupuncture is that there is a substance, called qi (this is the alphabetical, or pin-yin version of the word and is pronounced “chi”), which circulates everywhere in the body and the mind, and that this circulation can be affected in different ways by the insertion and manipulation of acupuncture needles. There is no single English word which can translate the concept of qi, although the most common one is “energy.” This is a poor translation, for many reasons, and can lead to some unhelpful misunderstandings. “Work” might be a better translation, and yet it is difficult for us to conceive of “work” circulating around the body. The Chinese language, which allows verbs and nouns to stand in for one another more readily, gives its speakers no difficulty with such a concept.
Our current understanding of physiology does highlight the existence of two main systems for communication between one part of the body and another. The nervous system, which consists of the brain and its extensive network of nerves, reaches practically every part of the body. Working closely with it is the endocrine system, which consists of a number of hormone-releasing glands located throughout the brain and the body. Hormones can quickly circulate throughout the body by means of the vascular network (arteries, capillaries and veins), which also reaches everywhere. Less well studied, are the endogenously produced electrical currents and fields in the body, which may connect different tissue systems in a more diffuse and less rapid way by means of the intercellular tissue fluid. It may be that the concept of qi circulation is connected in some way to early clinical observations of the effects of such physiological electrical states and flows, or to their effects on the complex systems of communication between brain, mind and body via nerves and hormones. Traditional theorists were not then in a position to measure electrical conduction along nerves, nor to analyse the chemical or electrical features of biological systems. Nevertheless, they were in a position to observe the effects of such systems at the macro level in their patients.
In particular, the measurable long-term effects of stress hormones, such as cortisol and adrenaline (also known as epinephrine), correspond with many of the changes the traditional theorists ascribed to their observation of “emotions” as an internal cause of disease, while the measurable effects of biological pathogenic invasion correspond with many of the changes the traditional theorists ascrived to their observations of “climate factors” as an external cause of disease.