[Some misunderstandings of deqi phenomenon: from historic review to experimental study]

In this paper, the authors trace back to the historic source of deqi and needling sensation, and probe the misunderstanding course of the feeling of sourness, numbness, distension, aching or heaviness used as synonym of deqi, and explore and introduce the modern significance and experimental studies of deqi. Although there are arguments in relationship between the feeling of sourness, numbness, distension, aching or heaviness after acupuncture and effect of acupuncture at home and abroad, in fact, this is a misunderstanding of needling sensation replacing deqi. Sometimes acupuncture possibly does not induce sourness, numbness, distension, aching or heaviness, but it also induces patient's comfortable sensation and at the same time acupuncture practitioners possibly have a sensation under the hand, which is at the state of deqi. The two states will be detected by fMRI in experimental studies, so as to have indexes to be followed for deqi or needling sensation.