Traditional Chinese medicine is a style of traditional medicine built on a foundation of more than 2,500 years of Chinese medical practice that includes various forms of herbal medicine, acupuncture, massage (tuina), exercise (qigong), and dietary therapy, but recently also influenced by modern Western medicine. TCM is widely used in Greater China (where it has long been the standard system of medicine), and is becoming increasingly popular and recognized worldwide (where it is primarily approached as alternative medicine). One of the basic tenets of TCM is that "the body's vital energy circulates through channels, called meridians, which have branches connected to bodily organs and functions. Concepts of the body and of disease used in TCM reflect its ancient origins and its emphasis on dynamic processes over material structure, similar to European humoral theory.
Scientific investigation has not found histological or physiological evidence for traditional Chinese concepts such as qi, meridians, and acupuncture points. The TCM theory and practice are not based upon scientific knowledge, and there is disagreement between TCM practitioners on what diagnosis and treatments should be used for any given patient. The effectiveness of Chinese herbal medicine remains poorly researched and documented. There are concerns over a number of potentially toxic plants, animal parts, and mineral Chinese medicinal. There are also concerns over illegal trade and transport of endangered species including rhinoceroses and tigers, and the welfare of specially farmed animals including bears. A review of cost-effectiveness research for TCM found that studies had low levels of evidence, but so far have not shown benefit outcomes. Pharmaceutical research has explored the potential for creating new drugs from traditional remedies, with few successful results.