“…Serious side effects include cardiac tamponade [43, 44], pneumothorax [45, 46], endocarditis [47–49], hepatitis [50–52], chylothorax [53], and spinal cord injury [50, 54], and minor side effects include fainting [55, 56] and skin reactions [57–60]. Pneumothorax is the most common mechanical organ injury associated with acupuncture treatment [50, 61–64], and the related reports are from the United States [65–67], Canada [68], The Netherlands [69, 70], France [71], Norway [63], Portugal [72, 73], Denmark [74], Taiwan [75], Japan [50, 76], China [45, 77], and Hong Kong [78]. Based on the facts mentioned above, we understand that the safe needling depth for acupuncture therapy is a very important issue for clinical practice.…”