Acupuncture is a technique of inserting and manipulating fine filiform needles into specific points on the body with the aim of relieving pain and for therapeutic purposes. According to acupuncture theory, these acupuncture points lie along meridians along which qi, a kind of vital energy, is said to flow. There is no generally-accepted anatomical or histological basis for these concepts, and modern acupuncturists tend to view them in functional rather than structural terms, (viz. as a useful metaphor in guiding evaluation and care of patients). Acupuncture is thought to have originated in China and is most commonly associated with Traditional Chinese Medicine (TCM). Different types of acupuncture (Classical Chinese, Japanese, Tibetan, and Korean acupuncture) are practiced and taught throughout the world.

While acupuncture has been a subject of active scientific research since the late 20th century, its effects are not well-understood, and it remains controversial among researchers and clinicians. The body of evidence remains inconclusive but is active and growing, and a 2007 review by Edzard Ernst and colleagues finds that the "emerging clinical evidence seems to imply that acupuncture is effective for some but not all conditions".

The WHO, the National Center for Complementary and Alternative Medicine (NCCAM) of the National Institutes of Health (NIH), the American Medical Association (AMA) and various government reports have all studied and commented on the efficacy (or lack therof) of acupuncture. There is general agreement that acupuncture is safe when administered by well-trained practitioners using sterile needles, and that further research is warranted.

Treatment of acupuncture points may be performed along several layers of pathways, most commonly the twelve primary channels, or mai, located throughout the body. The first twelve channels correspond to systems of function: Lung, Large Intestine, Stomach, Spleen, Heart, Small Intestine, Bladder, Kidney, Pericardium, San Jiao (an intangible, also known as Triple Burner), Gall Bladder, and Liver. Other pathways include the Eight Extraordinary Pathways (Qi Jing Ba Mai), the Luo Vessels, the Divergents and the Sinew Channels. Ashi (tender) points are generally used for treatment of local pain.