Chinese researchers have published a systematic review of adverse events associated with acupuncture reported between 2000 and 2011. The investigators found 117 reports of 308 adverse events from 25 countries and regions. The main complications were bacterial infection caused by skin contact at acupoint sites. Internal injuries such as puncture of the lung were also reported. [Xu S and others. Adverse events of acupuncture: A systematic review of case reports. Evidence-Based Complementary and Alternative Medicine, Volume 2013, Article ID 581203] [pdf]