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. Of the eight extra meridians, only two have acupuncture points of their own. The other six meridians are “activated” by using a master and couple point technique which involves needling the acupuncture points located on the twelve main meridians that correspond to the particular extra meridian. 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 qi 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 within the orthodox Western medical paradigm.
According to the NIH consensus statement on acupuncture:
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.