Acupuncture (from Latin, ‘acus’ (needle) + ‘punctura’ (to puncture)) is the stimulation of specific acupuncture points along the skin of the body using thin needles. It can be associated with the application of heat, pressure, or laser light to these same points. Clinical practice varies depending on the country. Traditional acupuncture involves needle insertion, moxibustion, and cupping therapy. It is a form of alternative medicine and a key component of traditional Chinese medicine (TCM). According to TCM, stimulating specific acupuncture points corrects imbalances in the flow of qi through channels known as meridians. TCM theory and practice are not based upon scientific knowledge. Acupuncture aims to treat a range of conditions, though it is most commonly used for pain relief. It is rarely used alone but rather as an adjunct to other forms of treatment. Evidence on the effectiveness of acupuncture is “variable and inconsistent, even for single conditions”. An overview of high-quality Cochrane reviews suggested that acupuncture may alleviate some, but not all, kinds of pain. A systematic review of systematic reviews found that for reducing pain, real acupuncture was no better than sham acupuncture and concluded that there is little evidence that acupuncture is an effective treatment for reducing pain. Although minimally invasive, the puncturing of the skin with acupuncture needles poses problems when designing trials that adequately control for placebo effects. Some research results suggest acupuncture can alleviate pain, though other research consistently suggests that acupuncture’s effects are mainly due to placebo. The evidence suggests that short-term treatment with acupuncture does not produce long-term benefits. A systematic review concluded that the analgesic effect of acupuncture seemed to lack clinical relevance and could not be clearly distinguished from bias. Acupuncture is generally safe when done by an appropriately trained practitioner using clean technique and single-use needles. When properly delivered, it has a low rate of mostly minor adverse effects. Between 2000 and 2009, at least ninety-five cases of serious adverse events, including five deaths, were reported to have resulted from acupuncture. Many of these cases occurred in developed countries and many were due to malpractice. The most frequently reported adverse events were pneumothorax and infections. Since serious adverse events continue to be reported, it is recommended that acupuncturists be trained sufficiently to reduce the risk. A meta-analysis found that acupuncture for chronic low back pain was cost-effective as an adjunct to standard care, but not as a substitute for standard care except in cases where comorbid depression presented, while a systematic review found insufficient evidence for the cost-effectiveness of acupuncture in the treatment of chronic low back pain. Acupuncture has been the subject of active scientific research, both in regard to its basis and therapeutic effectiveness, since the late 20th century. Scientific investigation has not found any histological or physiological evidence for traditional Chinese concepts such as qi, meridians, and acupuncture points. In response, some contemporary practitioners use acupuncture without following the traditional Chinese approach and have abandoned the concepts of qi and meridians as pseudoscientific. A Nature editorial described TCM as “fraught with pseudoscience”, and said that the most obvious reason why it hasn’t delivered many cures is that the majority of its treatments have no logical mechanism of action. Acupuncture is currently used widely throughout China and many other countries, including the United States. It is uncertain exactly when acupuncture originated or how it evolved, but it is generally thought to derive from ancient China. In Chinese history the introduction of acupuncture is attributed to the emperor Shennong. Hieroglyphs and pictographs have been found dating from the Shang Dynasty (1600–1100 BCE) that suggest acupuncture along with moxibustion was in practice.