Acupuncture is a type of alternative medicine that treats patients by insertion and manipulation of solid, generally thin needles in the body.
Through its origins, acupuncture has been embedded in the concepts of Traditional Chinese medicine (TCM). Its general theory is based on the premise that bodily functions are regulated by the flow of an energy-like entity called qi. Acupuncture aims to correct imbalances in the flow of qi by stimulation of anatomical locations on or under the skin called acupuncture points, most of which are connected by channels known as meridians. Scientific research has failed to validate the existence of any of the TCM concepts and some contemporary practitioners needle the body without using a theoretical framework, instead selecting points based on their tenderness to pressure.
The earliest written record of acupuncture is found in the Huangdi Neijing (黄帝内经; translated as The Yellow Emperor's Inner Canon), dated approximately 200 BCE. The practice of acupuncture expanded out of China into the areas now part of Japan, Korea and Taiwan, diverging from the narrower theory and practice of mainland TCM in the process. A large number of contemporary practitioners outside of China, particularly Europe, follow these non-TCM practices. The most notable difference is that these other approaches often are primarily acupuncture, and do not incorporate Chinese herbal medicine.
Acupuncture proponents have claimed that it promotes general health, relieves pain, treats infertility, treats and prevents disease. Meanwhile, evidence for its effectiveness for anything but the relief of some types of pain and nausea has not been established. Systemic reviews have found conflicting results regarding the prevention of postoperative nausea and vomiting though a 2009 Cochrane review concluded stimulation of the P6 acupuncture point was as effective as antiemetic medications. Acupuncture also appears to have a small effect in the short-term management of some types of pain though a 2011 review of review articles concluded that, except for neck pain, acupuncture was of doubtful efficacy. It has been suggested that the positive results reported for acupuncture can be explained by placebo effects and publication bias and researchers have pointed out the difficulty in designing an adequate scientific control for any placebo effect acupuncture might have due to its invasiveness. The development and inclusion of retracting needles as a form of placebo control has resulted in a much larger number of studies concluding acupuncture's effects are due to placebo.
There is general agreement that acupuncture is safe when administered by well-trained practitioners using sterile needles but does carry small but serious risks and adverse effects including death. Accompanied by calls for more research, the use of acupuncture for certain conditions has been tentatively endorsed by the United States National Institutes of Health and National Center for Complementary and Alternative Medicine, the National Health Service of the United Kingdom, and the World Health Organization, though most of these endorsements have been criticized and it has been questioned whether research on acupuncture is a good use of limited research funding.