Acupuncture is thought to have originated in China and is most commonly associated with Traditional Chinese Medicine (TCM).
Acupuncture treatment regulates the flow of Qi and Blood, tonifying where there is deficiency, draining where there is excess, and promoting free flow where there is stagnation.
The effectiveness of acupuncture remains controversial in the scientific community, according to a review by Edzard Ernst and colleagues in 2007, which found that the body of evidence was growing, research is active, and that the "emerging clinical evidence seems to imply that acupuncture is effective for some but not all conditions".
There is also general agreement that acupuncture is safe when administered by well-trained practitioners, and that further research is warranted.
Traditional Chinese medicine's acupuncture theory predates the use of the modern scientific method, and has received various criticisms based on modern scientific thinking.
In China, the practice of acupuncture can perhaps be traced as far back as the stone age, with the Bian shi, or sharpened stones.
Particularly important in acupuncture is the free flow of Qi, a difficult-to-translate concept that pervades Chinese philosophy and is commonly translated as "vital energy").
Most of the main acupuncture points are found on the "twelve main meridians" and two of the "eight extra meridians" (Du Mai and Ren Mai) a total of "fourteen channels", which are described in classical and traditional chinese medical texts, as pathways through which Qi and "Blood" flow.
Treatment of acupuncture points may be performed along several layers of pathways, most commonly the twelve primary channels, or mai, located throughout the body.