Acupuncture and Chinese Medicine

Acupuncture chart from the Ming dynasty.

Acupuncture (from Lat. acus, "needle" (noun), and pungere, "prick" (verb) or in Standard Mandarin, zhēn jǐu (針灸), is one of the main branches of Traditional Chinese Medicine (others being herbal medicine and tui na). It is a therapeutic technique from that framework intended to restore health and well-being. The term acupuncture is often used by Westerners to refer to Chinese medicine generally. The technique involves the insertion of needles into "acupuncture points" on the body by trained practitioners. The needles most commonly used in present-day practice are made of stainless steel and are of approximately the same diameter as a medium thickness guitar string (from approximately .01" to .02"). Although the clinical efficacy of this practice is debated, the traditional theory underlying its mechanisms has no basis in modern scientific conceptions of physiology and is therefore considered by its critics to be a pseudoscience. While many of its practitioners and proponents promote it in a modern, clinical manner, acupuncture and related practices predate modern concepts of science.

In China, the practice of acupuncture can perhaps be traced as far back as the 1^st millennium BC, and archeological evidence has been identified with the period of the Han dynasty (from 202 BC to 220 AD). The practice spread centuries ago into many parts of Asia; in modern times it is a component of traditional Chinese medicine (TCM), and forms of it are also described in the literature of traditional Korean medicine where it is called chimsul. It is also important in Kampo, the traditional medicine system of Japan.

Recent examinations of Ötzi,[1][2] a 5000 year old mummy found in the Alps, have located over fifty tattoos on Ötzi's body, some of which are located on acupuncture points that would today be used to treat ailments Ötzi suffered from. Some scientists believe that this is evidence that practices similar to acupuncture were practiced elsewhere in Eurasia during the early bronze age.

Medical law in the United States regarding acupuncture varies widely from state to state. Notably, states furthest to the west (Hawaii most particularly, California, etc.) have the most comprehensive and erudite laws and regulations regarding acupuncture. In many U.S. states -- those furthest to the east -- medical doctors (M.D.s) are permitted to practice acupuncture with no specific training in acupuncture. In some states, acupuncturists are required to work with an M.D. in a subservient relationship, even if the M.D. has no training in acupuncture. Contrastingly, Hawaii forbids M.D.s to practice acupuncture unless they have received specific training in it and have demonstrated related competency.

The consensus of Western-trained medical doctors and medical-research specialists on therapeutic efficacy is that:

• acupuncture is at least as effective as a placebo in some situations;
• as of 2004, acupuncture is more effective than placebo acupuncture in relieving pain caused by osteoarthritis; and
• continued research on the possible value of acupuncture in various areas of medicine is worthwhile.

Warming an acupuncture point, typically by moxibustion (the burning of mugwort), is a different treatment than acupuncture by itself and is often, but not exclusively, used as a supplementing treatment. The Chinese term zhēn jǐu (針灸), commoned used to refer to acupuncture, comes from zhen meaning "needle", and jiu meaning "moxibustion". Moxibustion is still used in the 21^st century to varying degrees among the schools of traditional Chinese medicine. For example, one well known technique is to insert the needle at the desired acupuncture point, attach dried mugwort to the external end of an acupuncture needle, and then ignite the mugwort. The mugwort will then smolder for several minutes (depending on the amount adhered to the needle) and conduct heat through the needle to the tissue surrounding the needle in the patient's body.

Most modern acupuncturists use disposable stainless steel needles of very fine diameter (approximately .015"), sterilized with ethylene oxide or by autoclave. The upper third of these needles is wound with a thicker wire (typically bronze) to stiffen the needle, provide a handle for the acupuncturist to grasp while inserting the needle, and also provide a surface to which dried mugwort will more easily adhere.

Theory

Acupuncture treats the human body as a whole that involves several "systems of function" that are in many cases associated with (but not identified on a one-to-one basis with) physical organs. Some systems of function, such as the "triple heater" (San Jiao, also called the "triple burner") have no corresponding physical organ. Disease is understood as a loss of homeostasis among the several systems of function, and treatment of disease is attempted by modifying the activity of one or more systems of function through the activity of needles, pressure, heat, etc. on sensitive parts of the body of small volume traditionally called "acupuncture points" in English, or "xue" (穴, cavities) in Chinese.

Treatment of acupuncture points may be performed along the twelve main or eight extra meridians, located throughout the body. Ten of the main meridians are named after organs of the body (Heart, Liver, etc.), and the other two are named after so called body functions (Heart Protector or Pericardium, and San Jiao). The two most important of the eight "extra" meridians are situated on the midline of the anterior and posterior aspects of the trunk and head. The twelve primary meridians run vertically, bilaterally, and symmetrically and every channel corresponds to and connects internally with one of the twelve Zang Fu ("organs"). This means that there are six yin and six yang channels. There are three yin and three yang channels on each arm, and three yin and three yang on each leg.

The three yin channels of the hand (Lung, Pericardium, and Heart) begin on the chest and travel along the inner surface (mostly the anterior portion) of the arm to the hand.

The three yang channels of the hand (Large intestine, San Jiao, and Small intestine) begin on the hand and travel along the outer surface (mostly the posterior portion) of the arm to the head.

The three yang channels of the foot (Stomach, Gallbladder, and Bladder) begin on the face, in the region of the eye, and travels down the body and along the outer surface (mostly the anterior and lateral portion) of the leg to the foot.

The three yin channels of the foot (Spleen, Liver, and Kidney) begin on the foot and travel along the inner surface (mostly posterior and medial portion) of the leg to the chest or flank.

The movement of qi through each of the twelve channels is comprised of an internal and an external pathway. The external pathway is what is normally shown on an acupuncture chart and it is relatively superficial. All the acupuncture points of a channel lie on its external pathway. The internal pathways are the deep course of the channel where it enters the body cavities and related Zang-Fu organs. The superficial pathways of the twelve channels describe three complete circuits of the body.

The distribution of energy through the meridians is said to be as follows: Lung channel of hand taiyin to Large Intestine channel of hand yangming to Stomach channel of foot yangming to Spleen channel of foot taiyin to Heart channel of hand shaoyin to Small Intestine channel of hand taiyang to Bladder channel of foot taiyang to Kidney channel of foot shaoyin to Pericardium channel of hand jueyin to San Jiao channel of hand shaoyang to Gallbladder channel of foot shaoyang to Liver channel of foot jueyin then back to the Lung channel of hand taiyin

Traditional Chinese medical theory holds that acupuncture works by normalizing the balance of qi "vital energy" throughout the body. Pain or illnesses are treated by attempting to remedy local or systemic accumulations or deficiencies of qi. Pain is considered to indicate blockage or stagnation of the flow of qi, and an axiom of the medical literature of acupuncture is "no pain, no blockage; no blockage, no pain".

Many patients claim to experience the sensations of stimulus known in Chinese as "deqi" (得氣 "obtaining the qi"). This kind of sensation was historically considered to be evidence of effectively locating the desired point. There are some electronic devices now available which will make a noise when what they have been programmed to describe as the "correct" acupuncture point is pressed.

The acupuncturist will decide which points to treat by thoroughly questioning the patient, and utilizing the diagnostic skills of traditional Chinese medicine which include observation of the left and right radial pulses at three levels of imposed pressure and analysis of the tongue coating, color and the absence or presence of teeth marks around the edge.

There are also theories being developed to explain effects observed for acupuncture by within the orthodox Western medical paradigm.

There are various schools of acupuncture theory, including

• the original TCM method
• Zang Fu theory
• medical acupuncture

An example of acupuncture practice

Acupuncture

In western medicine, vascular headaches (the kind that are accompanied by throbbing veins in the temples) are typically treated with analgesics such as aspirin and/or by the use of agents such as niacin that dilate the affected blood vessels in the scalp, but in acupuncture a common treatment for such headaches is to stimulate the sensitive points that are located roughly in the center of the webs between the thumbs and the palms of the patient, the gǔ hé points. The theory of acupuncture states that these points are associated with the digestive system (the large intestine), and that one is acting to relax some kind of hyperactive state in the gastro-intestinal system. Three kinds of sensation are associated with this treatment, sensations that are stronger than those that would be felt by a patient not suffering from a vascular headache: (1) Extreme sensitivity to pain at the points in the webs of the thumbs. (2) In bad headaches, a feeling of nausea that persists for roughly the same period as the stimulation being administered to the webs of the thumbs. (3) Simultaneous relief of the headache. (See Zhen Jiu Xue, p. 177f et passim.)

Benefits (proven and purported)

Although accepted as a medical treatment in Asia for millennia, acupuncture's arrival in the West has sparked much controversy. Acupuncture has eluded scientific explanation to some degree. However, in 1997, the NIH issued a consensus statement on acupuncture that concluded that

there is sufficient evidence of acupuncture's value to expand its use into conventional medicine and to encourage further studies of its physiology and clinical value.

The NIH statement noted that

the data in support of acupuncture are as strong as those for many accepted Western medical therapies

and added that

the incidence of adverse effects is substantially lower than that of many drugs or other accepted medical procedures used for the same condition. For example, musculoskeletal conditions, such as fibromyalgia, myofascial pain, and tennis elbow... are conditions for which acupuncture may be beneficial. These painful conditions are often treated with, among other things, anti-inflammatory medications (aspirin, ibuprofen, etc.) or with steroid injections. Both medical interventions have a potential for deleterious side effects but are still widely used and are considered acceptable treatments.

The NIH consensus statement noted that

there is clear evidence that needle acupuncture is efficacious for adult postoperative and chemotherapy nausea and vomiting and probably for the nausea of pregnancy... There is reasonable evidence of efficacy for postoperative dental pain... reasonable studies (although sometimes only single studies) showing relief of pain with acupuncture on diverse pain conditions such as menstrual cramps, tennis elbow, and fibromyalgia...

However,

acupuncture does not demonstrate efficacy for cessation of smoking and may not be efficacious for some other conditions.

In 1999, clinical researchers reported that inserting the fine needles into specific body points triggers the production of endorphins [3].

Potential risks

Acupuncture is an invasive technique, and therefore not without risk. Hematoma may result from accidental puncture of any circulatory structure. Nerve injury can result from the accidental puncture of any nerve. Brain damage or stroke is possible with very deep needling at the base of skull. Also rare but possible is pneumothorax from deep needling into the lung, and kidney damage from deep needling in the low back. Needling over an occult sternal foramen (an undetectable hole in the breastbone which can occur in up to 10% of people) may result in a potentially fatal haemopericardium. There are warnings in texts on acupuncture regarding both the depth to which needles may be inserted, and the angle at which needles may be inserted. Both these instructions are intended to prevent acupuncture needles from penetrating dangerously into the body.

Accupuncture stimulates the production of adrenocorticotropic hormone (ACTH) and oxytocin in some patients, which can lead to harm to fetuses.

Needles that are not properly sterilized can transfer diseases such as HIV and hepatitis. In the United Kingdom, British Acupuncture Council (BAcC) members observe the Code of Safe Practice which lays down stringent standards of hygiene and sterilisation for other equipment - members use single-use pre-sterilised disposable needles, which are permanently withdrawn from service after being used in treatment. Similar standards apply in most jurisdictions in the United States. Sometimes, when treating pain or using acupuncture as an anesthetic, a mild electrical current is applied to the needles. This stimulates the nerve cells in the area of the needles so that they become depleted of the chemicals needed to transmit signals (please note this is not an acupuncture effect!). Prolonged stimulation of nerve cells in this way can cause irreversible damage.

Severe injury from acupuncture is extremely rare, but not unheard of. Well-trained, licensed and experienced acupuncturists are less likely to injure a patient. However, in many countries anyone can call himself an acupuncturist, there are no legal requirements with regard to training and education, nor are licensing boards regulated in any way, making it very hard to assess the actual value of licenses and training of acupuncturists. The NIH consensus panel made the following statement about the risks associated with acupuncture: “Adverse side effects of acupuncture are extremely low and often lower than conventional treatments. In a UK study of almost 2000 practitioners covering over 34,000 treatments, there were no serious adverse events and only 43 minor adverse events [4].

In the USA the National Certification Commission for Acupuncture and Oriental Medicine tests practitioners to ensure they are knowledgeable about Chinese medicine. Many states require this test for licensing, but each state has its own laws and requirements.

Most acupuncturists in the USA use sterile one-time-use needles. Some still use reusable needles and an autoclave but this practice is declining due to its cost, time and the possibility of failure in sterilizing the needles.

Controversy as to effectiveness

A private watchdog group, the National Council Against Health Fraud has stated:

• Acupuncture is an unproven modality of treatment.
• Its theory and practice are based on primitive and fanciful concepts of health and disease that bear no relationship to present scientific knowledge.
• Research during the past 20 years has not demonstrated that acupuncture is effective against any disease.
• Perceived effects of acupuncture are probably due to a combination of expectation, suggestion, counter-irritation, conditioning, the regressive fallacy and other psychological mechanisms.
• The use of acupuncture should be restricted to appropriate research settings.
• Insurance companies should not be required by law to cover acupuncture treatment.
• Licensure of lay acupuncturists should be phased out.
• Consumers who wish to try acupuncture should discuss their situation with a knowledgeable physician who has no commercial interest.

Reference: Sampson W and others. Acupuncture: The position paper of the National Council Against Health Fraud. Clinical Journal of Pain 7:162-166, 1991.

A Consensus Development Conference held in 1997, sponsored among others by the National Institutes of Health stated:

Despite considerable efforts to understand the anatomy and physiology of the "acupuncture points", the definition and characterization of these points remains controversial. Even more elusive is the basis of some of the key traditional Eastern medical concepts such as the circulation of Qi, the meridian system, and the five phases theory, which are difficult to reconcile with contemporary biomedical information but continue to play an important role in the evaluation of patients and the formulation of treatment in acupuncture.

In short, the treatment and diagnosis of acupuncturists are not based on concepts that blend well with those used by contemporary medical science.

Three Dutch epidemiologists have analyzed 51 controlled studies of acupuncture, in which acupuncture was used to treat chronic pain. Their conclusion was that

the quality of even the better studies proved to be mediocre. . . . The efficacy of acupuncture in the treatment of chronic pain remains doubtful.

Reports of acupuncture used to treat various addictions (heroin, cigarettes, alcohol) were also analyzed. The conclusion was that

claims that acupuncture is effective as a therapy for these conditions are not supported by sound clinical research.

References: Ter Riet G, Kleijnen J, Knipschild P.: ‘Acupuncture and chronic pain: A criteria-based meta-analysis. Clinical Epidemiology 43:1191-1199, 1990’ and (from the same authors) ‘A meta-analysis of studies into the effect of acupuncture on addiction. British Journal of General Practice 40:379-382, 1990.’

The University of Heidelberg has developed a “fake needle” to use as placebo-needle. It is a needle with a blunt tip that can slide into the handle, giving the illusion that it penetrates the skin. In tests, volunteers did not notice that the needle did not actually penetrate their skin (Reference: Streitberger K, Kleinhenz J. Introducing a placebo needle into acupuncture research. Lancet 352:364-365, 1998). They used this needle in 2004 in a study of postoperative nausea and vomiting (PONV) in women who underwent breast or gynecologic surgery. The group consisted of 220 women. Acupuncture was applied on the acupuncture point “Pericardium 6 (P6),” which is on the inside of the forearm. Part of the group was treated with real needles, the other part (the control group) with the fake needles. They reported: 'We could not prove our hypothesis that acupuncture is more effective than placebo acupuncture in the prevention of PONV.' (or to put it more plainly) 'There was almost no difference in the occurrence of PONV between acupuncture (38.7%) and placebo (40.3%) in the subgroup of patients having breast surgery. ' (Reference: Streitberger K and others: Acupuncture compared to placebo-acupuncture for postoperative nausea and vomiting prophylaxis: A randomised placebo-controlled patient and observer blind trial. Anesthesia 59:142-149, 2004.)

What is less often remarked upon is that the Heidelberg study above went on to comment:

PONV was reduced by acupuncture about 18.5% (from 67.4% to 48.9%) in the subgroup of patients with gynaecological surgery, which was close to our expectation of a reduction of 20%. Therefore, our study might suggest that acupuncture is effective for PONV prophylaxis in patients having gynaecological surgery but not in those having breast surgery. However, our study had insufficient power for this question because it was not designed to prove this new hypothesis.

They noted that previous studies found that acupuncture worked particularly well on gynaecological surgery. They also pointed out that

A statistically significant result was achieved in the secondary outcome criteria of vomiting within 24 h after surgery.

but that, again, this result had to be viewed with caution as

Positive results in secondary endpoints or subgroup analysis might be due to multiple testing.

A more recent 2004 meta-analysis of the effects the same (P6) acupoint on Post-Operative Nausea and Vomiting (PONV) stated that

Twenty-six trials (n = 3347) were included, none of which reported adequate allocation concealment

(Allocation concealment prevents researchers from (unconsciously or otherwise) influencing which participants are assigned to a given intervention group.)

There were significant reductions in the risks of nausea (RR 0.72, 95% CI 0.59 to 0.89), vomiting (RR 0.71, 95% CI 0.56 to 0.91) and the need for rescue antiemetics (RR 0.76, 95% CI 0.58 to 1.00) in the P6 acupoint stimulation group compared with the sham treatment, although many of the trials were heterogeneous. There was no evidence of difference in the risk of nausea and vomiting in the P6 acupoint stimulation group versus individual antiemetic groups. However, when different antiemetics were pooled, there was significant reduction in the risk of nausea but not vomiting in the P6 acupoint stimulation group compared with the antiemetic group (RR 0.70, 95% CI 0.50 to 0.98; RR 0.92, 95% CI 0.65 to 1.29 respectively). The side effects associated with P6 acupoint stimulation were minor.

The reviewers concluded:

This systematic review supports the use of P6 acupoint stimulation in patients without antiemetic prophylaxis. Compared with antiemetic prophylaxis, P6 acupoint stimulation seems to reduce the risk of nausea but not vomiting.

Of course, this meta-analysis has been criticised for the lack of allocation concealment in any of the trials.

• Cochrane Library meta-analysis of the effect of the P6 acupuncture point on PONV

In a recent study it was discovered that genuine acupuncture needles created objective changes in brain states as measured by positron emission tomography (PET), as opposed to the use of sham needles, especially in brain areas related to pain reduction. But random placement of the needles (placebo acupuncture) also had that effect. The authors of the study state: 'These results suggest that real acupuncture has a specific physiological effect'

• Expectancy and belief modulate the neuronal substrates of pain treated by acupuncture, NeuroImage, 25, 4

According to the NIH Consensus Statement on Acupuncture:

Acupuncture as a therapeutic intervention is widely practiced in the United States. While there have been many studies of its potential usefulness, many of these studies provide equivocal results because of design, sample size, and other factors. The issue is further complicated by inherent difficulties in the use of appropriate controls, such as placebos and sham acupuncture groups. However, promising results have emerged, for example, showing efficacy of acupuncture in adult postoperative and chemotherapy nausea and vomiting and in postoperative dental pain. There are other situations such as addiction, stroke rehabilitation, headache, menstrual cramps, tennis elbow, fibromyalgia, myofascial pain, osteoarthritis, low back pain, carpal tunnel syndrome, and asthma, in which acupuncture may be useful as an adjunct treatment or an acceptable alternative or be included in a comprehensive management program. Further research is likely to uncover additional areas where acupuncture interventions will be useful.

• NCCAM research summaries on acupuncture

Another Cochrane meta-analysis probably sums up the status quo best:

Overall, the existing evidence supports the value of acupuncture for the treatment of idiopathic headaches. However, the quality and amount of evidence are not fully convincing. There is an urgent need for well-planned, large-scale studies to assess the effectiveness and cost-effectiveness of acupuncture under real-life conditions.

• Cochrane review of acupuncture for idiopathic headache.

The British Medical Journal reports ( DOI: 10.1136/bmj.38512.405440.8F ) that in a study of 270 tension headache sufferers in Munich, needles inserted at random points on the body were just as effective as needles inserted at traditional acupuncture points. This would suggest that any observed effect is due to the body's response to the needles, rather than the interaction with the claimed "energy flows".

• BMJ Abstract

Proponents continue to claim that the scientific jury is still out on the effectiveness of acupuncture, with existing evidence slightly favouring the proposition that it can be effective in some cases for some conditions. However, almost all the research on the effectiveness of acupuncture is of poor quality and can be criticised on various grounds. The validity of acupuncture is discounted by a great majority of the mainstream medical and scientific community and much more research (of a much higher quality) would need to be done before the effectiveness of acupuncture could be accepted within the medical community.

See: http://nccam.nih.gov/health/acupuncture/

See also

• Acupressure
• Chin na
• Chinese martial arts
• Electroacupuncture
• Intramuscular Stimulation
• Qi
• Qigong
• T'ai Chi Ch'uan
• Taoism

External links

• Search for “acupuncture” on PubMed - US National Library of Medicine search engine with thousands of scientific articles on acupuncture
• Acupuncture news, research papers, information and discussion - An Australian Acupuncture site updated regularly.
• Acupuncture News
• [5]Topish Acupuncture and History on Traditional Chinese Medicine
• NIH 1997 Consensus Statement on Acupuncture
• Acupuncture: Review And Analysis Of Reports On Controlled Clinical Trials, World Health Organization, 2002
• Five Element Acupuncture Information Site A site devoted to the 5 Element Style of Acupuncture
• Acupuncture, The Facts. - An article.
• Rotten Library Article on Acupuncture
• How acupuncture works explained
• Open Directory: Acupuncture and Chinese Medicine. - A collection of links, mostly to pro-acupuncture sites.
• Acumedico forum, articles and discussion - An Israeli acupuncture site.
• The Skeptics dictionary on acupuncture
• The Straight Dope on Acupuncture - A critical site
• Acupuncture past and present (1973)
• The uncharted wilderness of acupuncture (1973)
• A report from a physician who visited China after Nixon
• Acupuncture, Qigong, and "Chinese Medicine" by Stephen Barrett, M.D. (Quackwatch.org)
• Effects of acupuncture on gastroparesis study
• British Medical Acupuncture Society
• Acupuncture Clinics & Specialists - Informational resource and nationwide directory of acupuncturists and clinics.
• Chinese medicine, Chinese Herbal Medicine and Acupuncture Medline Most recent research articles on Chinese medicine, Chinese Herbal Medicine and Acupuncture from Medline/Entrez PubMed

Bibliography

• Acupuncture. NIH Consensus Statement Online 1997 Nov 3-5; month, day; 15(5):1-34.
• Richardson PH, Vincent CA. The evaluation of therapeutic acupuncture: concepts and methods. Pain 24:1-13, 1986.
• Richardson PH, Vincent CA. Acupuncture for the treatment of pain. Pain 24:1540, 1986.
• Ter Riet G et al. The effectiveness of acupuncture. Huisarts Wet 32:170-175, 176-181, 308-312, 1989.
• Zhen Jiu Xue/ Tai-zhong Association of Chinese Medical Doctors, the Publishing Committee on Acupuncture, 1976. (Chinese characters for all of this to follow.)

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Acupuncture

TCM shop in Tsim Sha Tsui, Hong Kong.

Traditional Chinese medicine (TCM) also known simply as Chinese medicine (Chinese: 中醫學, zhōngyī xué, or 中药学, zhōngyaò xué) is the name commonly given to a range of traditional medical practices used in China that have developed over the course of several thousand years of history. It is also regarded as an instance of oriental medicine, a term which may include other traditional Asian medical systems such as Japanese, Korean, Tibetan, and Mongolian medicine. Chinese medicine principally employs a method of analysis and synthesis, inquiring on a macro-level into the internal systems of the human body and their mutual relationships with the internal and external environment in an attempt to gain an understanding of the fundamental laws which govern the functioning of the human organism, and to apply this understanding to the treatment and prevention of disease, and health maintenance. TCM is rooted in a unique, comprehensive and systematic theoretical structure which includes the Theory of the Five Elements, the human body Meridian system, Yin-yang and other systems. Treatment is conducted with reference to this philosophical framework.

Uses

In the West, TCM is often considered alternative medicine; however, in mainland China and Taiwan, TCM is widely considered to be an integral part of the health care system. The term TCM is sometimes used specifically within the field of Chinese medicine to refer to the standardized set of theories and practices introduced in the mid-20th century under the government of Mao, as distinguished from related traditional theories and practices preserved by people in Taiwan, Hong Kong and by the overseas Chinese. The more general sense is meant in this article.

TCM developed as a form of noninvasive therapeutic intervention (also described as folk medicine or traditional medicine) rooted in ancient belief systems, including traditional religious concepts. Chinese medical practitioners before the 19th century relied essentially on observation, trial and error. Like their counterparts in the West, they had a very different understanding of infection which predated the discovery of bacteria, viruses (germ theory of disease) or cellular structures and little knowledge of organic chemistry, relying mainly on distinctly observational medical theory describing the nature of infections and remedies actions. Traditions, and observations based on their theory, along with three millennia of practical experience guided their courses of treatment and instruction in diagnostic principles.

Unlike other forms of traditional medicine which have largely become extinct, traditional Chinese medicine continues as a distinct branch of modern medical practice, and within China, it is an important part of the public health care system. There are thousands of years of empirical knowledge about TCM conceptualized and recorded in terms appropriate to that system, and in recent decades there has been an effort to integrate the discoveries made by traditional Chinese medicine with the discoveries made by workers in the Western medical traditions. One important component of this work is to use the instrumentation and the methodological tools available via Western medicine to investigate observations made and hypotheses raised by the Chinese tradition.

That this effort has occurred is surprising to many for a number of reasons. In most of the world, indigenous medical practices have been supplanted by practices brought from the West, while in Chinese societies, this has not occurred and shows no sign of occurring. Furthermore, many have found it peculiar that Chinese medicine remains a distinct branch of medicine separate from Western medicine, while the same has not happened with other intellectual fields. There is, for example, no longer a distinct branch of Chinese