Acupuncture is a collection of procedures involving penetration of the skin with needles in order to stimulate certain points on the body. In its classical form, it is a characteristic component of traditional Chinese medicine (TCM), a form of alternative medicine, and one of the oldest healing practices in the world.

According to traditional Chinese medicine, stimulating specific acupuncture points corrects imbalances in the flow of qi through channels known as meridians. Scientific investigation has not found any histological or physiological correlates for traditional Chinese concepts such as qi, meridians, and acupuncture points, and some contemporary practitioners use acupuncture without following the traditional Chinese approach.

Research suggests that traditional forms of acupuncture are more effective than placebos in the relief of certain types of pain and post-operative nausea. Recent systematic reviews found that acupuncture also seems to be a promising treatment option for anxiety, sleep disturbances, and depression, but further research is needed in these regards. Although minimally invasive, the puncturing of the skin with acupuncture needles poses problems when designing trials that adequately control for placebo effects. A number of studies comparing traditional acupuncture to sham procedures found that both sham and traditional acupuncture were superior to usual care but were themselves equivalent; findings apparently at odds with traditional Chinese theories regarding acupuncture point specificity.

Acupuncture's use for certain conditions has been endorsed by the United States National Institutes of Health, the National Health Service of the United Kingdom, the World Health Organization, and the National Center for Complementary and Alternative Medicine. Some scientists have criticized these endorsements as being unduly credulous and not including objections to or criticisms of the research used to support acupuncture's effectiveness. There is general agreement that acupuncture is relatively safe when administered by qualified practitioners using sterile needles and carries a very low risk of serious adverse effects.

The general theory of acupuncture is based on the premise that bodily functions are regulated by an energy called qi which flows through the body; disruptions of this flow are believed to be responsible for disease. Acupuncture describes a family of procedures aiming to correct imbalances in the flow of qi by stimulation of anatomical locations on or under the skin (usually called acupuncture points or acupoints), by a variety of techniques. The most common mechanism of stimulation of acupuncture points employs penetration of the skin by thin metal needles, which are manipulated manually or by electrical stimulation.

Acupuncture needles are typically made of stainless steel wire. They are usually disposable, but reusable needles are sometimes used as well, though they must be sterilized between uses.

Needles vary in length between 13 to 130 millimetres (0.51 to 5.1 in), with shorter needles used near the face and eyes, and longer needles in more fleshy areas; needle diameters vary from 0.16 mm (0.006 in) to 0.46 mm (0.018 in), with thicker needles used on more robust patients. Thinner needles may be flexible and require tubes for insertion. The tip of the needle should not be made too sharp to prevent breakage, although blunt needles cause more pain.

Apart from the usual filiform needle, there are also other needle types which can be utilized, such as three-edged needles and the Nine Ancient Needles. Japanese acupuncturists use extremely thin needles that are used superficially, sometimes without penetrating the skin, and surrounded by a guide tube (a technique adopted in China and the West). Korean acupuncture uses copper needles and has a greater focus on the hand.

Acupuncture chart from the Ming Dynasty (c. 1368-1644)

The precise start date of acupuncture's invention in ancient China and how it evolved from early times are uncertain. One explanation is that Han Chinese doctors observed that some soldiers wounded in battle by arrows were believed to have been cured of chronic afflictions that were otherwise untreated, and there are variations on this idea. Sharpened stones known as Bian shi have been found in China, suggesting the practice may date to the Neolithic or possibly even earlier in the Stone Age. Hieroglyphs and pictographs have been found dating from the Shang Dynasty (1600-1100 BCE) which suggests that acupuncture was practiced along with moxibustion. It has also been suggested that acupuncture has its origins in bloodletting or demonology.

Despite improvements in metallurgy over centuries, it was not until the 2nd century BCE during the Han Dynasty that stone and bone needles were replaced with metal. The earliest examples of metal needles were found in a tomb dated to c. 113 BCE, though their use might not necessarily have been acupuncture. The earliest example of the unseen meridians used for diagnosis and treatment are dated to the second century BCE but these records do not mention needling, while the earliest reference to therapeutic needling occurs in the historical Shiji text but does not mention the meridians and may be a reference to lancing rather than acupuncture.

The earliest written record of acupuncture is found in the Huangdi Neijing (The Yellow Emperor's Inner Canon), dated approximately 200 BCE. It does not distinguish between acupuncture and moxibustion and gives the same indication for both treatments. The Mawangdui texts, which also date from the 2nd century BCE (though antedating both the Shiji and Huangdi Neijing), mention the use of pointed stones to open abscesses, and moxibustion, but not acupuncture. However, by the 2nd century BCE, acupuncture replaced moxibustion as the primary treatment of systemic conditions.

The practice of acupuncture expanded out of China into the areas now part of Japan, Korea, Vietnam, and Taiwan, diverging from the narrower theory and practice of mainland TCM in the process. A large number of contemporary practitioners outside of China follow these non-TCM practices, particularly in Europe.

In Europe, examinations of the 5,000-year-old mummified body of Otzi the Iceman have identified 15 groups of tattoos on his body, some of which are located on what are now seen as contemporary acupuncture points. This has been cited as evidence that practices similar to acupuncture may have been practiced elsewhere in Eurasia during the early Bronze Age.

Korea is believed to be the second country that acupuncture spread to outside of China. Within Korea there is a legend that acupuncture was developed by the legendary emperor Dangun though it is more likely to have been brought into Korea from a Chinese colonial prefecture.

Around 90 works on acupuncture were written in China between the Han Dynasty and the Song Dynasty, and the Emperor Renzong of Song, in 1023, ordered the production of a bronze statuette depicting the meridians and acupuncture points then in use. However, after the end of the Song Dynasty, acupuncture lost status, and started to be seen as a technical profession, in comparison to the more scholarly profession of herbalism. It became rarer in the following centuries, and was associated with less prestigious practices like alchemy, shamanism, midwifery, and moxibustion.

Portuguese missionaries in the 16th century were among the first to bring reports of acupuncture to the West. Jacob de Bondt, a Dutch surgeon traveling in Asia, described the practice in both Japan and Java. However, in China itself the practice was increasingly associated with the lower-classes and illiterate practitioners.

In 1674, Hermann Buschoff, a Dutch priest in Batavia, published the first book on moxibustion (from Japanese mogusa) for the cure of arthritis. The first elaborate Western treatise on acupuncture was published in 1683 by Willem ten Rhijne, a Dutch physician who had worked at the Dutch trading post Dejima in Nagasaki for two years.

In 1757 the physician Xu Daqun described the further decline of acupuncture, saying it was a lost art, with few experts to instruct; its decline was attributed in part to the popularity of prescriptions and medications, as well as its association with the lower classes.

In 1822, an edict from the Chinese Emperor banned the practice and teaching of acupuncture within the Imperial Academy of Medicine outright, as unfit for practice by gentlemen-scholars. At this point, acupuncture was still cited in Europe with both skepticism and praise, with little study and only a small amount of experimentation.

In the early years after the Chinese Civil War, Chinese Communist Party leaders ridiculed traditional Chinese medicine, including acupuncture, as superstitious, irrational, and backward, claiming that it conflicted with the Party's dedication to science as the way of progress. Communist Party Chairman Mao Zedong later reversed this position, saying that “Chinese medicine and pharmacology are a great treasure house and efforts should be made to explore them and raise them to a higher level.”

Under Mao's leadership, in response to the lack of modern medical practitioners, acupuncture was revived and its theory rewritten to adhere to the political, economic, and logistic necessities of providing for the medical needs of China's population. Despite Mao proclaiming the practice of Chinese medicine to be “scientific”, the practice was based more on the materialist assumptions of Marxism in opposition to superstition rather than the Western practice of empirical investigation of nature.

Later in the 1950s, TCM's theory was again rewritten at Mao's insistence as a political response to the lack of unity between scientific and traditional Chinese medicine, and to correct the supposed “bourgeois thought of Western doctors of medicine.”

Acupuncture gained attention in the United States when President Richard Nixon visited China in 1972. During one part of the visit, the delegation was shown a patient undergoing major surgery while fully awake, ostensibly receiving acupuncture rather than anesthesia. Later it was found that the patients selected for the surgery had both a high pain tolerance and received heavy indoctrination before the operation; these demonstration cases were also frequently receiving morphine surreptitiously through an intravenous drip during the surgery.

In the 1980s, acupuncture gained attention and recognition in the United States, with the National Institutes of Health holding a consensus conference in 1997 that acknowledged acupuncture as a treatment for certain conditions and endorsed its use under specific circumstances. This attention helped it spread further in the West, though it has also led to more rigorous investigation and criticism.

Contemporary practice of acupuncture varies widely in terms of the theoretical basis and methods of practice. Some practitioners use traditional Chinese concepts, while others base their practice on the principles of modern medical science.

Many modern practitioners blend traditional acupuncture with Western medical concepts, which can include a focus on neuroanatomy, physiology, and evidence-based medicine. They may use acupuncture to treat a range of conditions, including pain, stress, and some internal disorders, while relying on current scientific understanding to guide their practice.

Acupuncture remains a subject of ongoing debate within the medical community. Some practitioners and patients report significant benefits, while others argue that observed effects may be due to placebo or other psychological factors. Researchers continue to investigate the efficacy and mechanisms of acupuncture, seeking to understand how and why it might work, and to define its place in contemporary medical practice.

Acupuncture spread to many countries over the centuries. Its introduction to Europe began in the 16th century and gained traction in the 17th and 18th centuries. It became more widely accepted and practiced in the West during the 19th and 20th centuries, especially following the visits of prominent figures and the increased availability of information on its techniques and benefits.

In the late 20th and early 21st centuries, acupuncture became more integrated into mainstream healthcare in many countries. In the United States, for example, acupuncture has been incorporated into many healthcare systems, including pain management and complementary therapies. Many countries have regulatory bodies that set standards for acupuncture practice and education, contributing to its professionalization and acceptance.

* “The Yellow Emperor's Classic of Medicine” – an ancient Chinese medical text that outlines acupuncture and other medical practices. * “Acupuncture: A Comprehensive Guide” by the American Academy of Medical Acupuncture. * “The Science and Practice of Acupuncture” – a text that explores both the scientific evidence and practical aspects of acupuncture. * “Acupuncture and Chinese Medicine: Roots and Rebirth” – a book detailing the historical and modern aspects of acupuncture.