The earliest documented system of acupuncture appeared in the Inner Classic of Huang Di around 100 BC. Gold and silver needles discovered in the tomb of Liu Sheng from that same era serve as the oldest archaeological evidence.
Acupuncture reached Europe in the second half of the 17th century when the surgeon-general of the Dutch East India Company met Japanese and Chinese practitioners. He published the first detailed description of acupuncture for Europeans in his 1683 work De Acupunctura.
No research has established any consistent anatomical structure or function for either acupuncture points or meridians. Scientific investigation has found no histological or physiological evidence for traditional concepts like qi meridians or yin-yang balance.
Needles vary in length between 13 millimeters and 150 millimeters with diameters ranging from 0.16 millimeters to 0.35 millimeters depending on patient robustness. Most needles are made of stainless steel making them flexible and preventing rusting or breaking.
Systematic reviews generally provide no good evidence that acupuncture benefits health beyond placebo effects except for shoulder pain and fibromyalgia. Research suggests therapeutic effects stem from non-specific factors rather than specific physiological mechanisms.
Between 2000 and 2009 ninety-five cases of serious adverse events including five deaths appeared in international records. Pneumothorax bacterial infections viral infections and cardiac injuries represented frequent severe outcomes.