Eighty-six people have been accidentally killed by badly trained acupuncturists over the past 45 years, according to Britain's leading expert on alternative medicine.
A review of patients who died soon after acupuncture found a history of punctured hearts and lungs, damaged arteries and livers, nerve problems, shock, infection and haemorrhage, largely caused by practitioners placing their needles incorrectly or failing to sterilise their equipment.
Many of the 86 patients, aged between 26 and 82 years old, died after being treated by acupuncturists in China or Japan, but a handful of fatalities were recorded in the US, Germany and Australia. The most recent death, of a 26-year-old woman in China, occurred last year.
The most common cause of death was a condition called pneumothorax, where air finds its way between the membranes that separate the lungs from the chest wall and causes the lungs to collapse.
In most of the cases, doctors were certain that acupuncture was to blame, but in some the cause was less clear.
Describing his research in the International Journal of Risk and Safety in Medicine, Edzard Ernst, professor of complementary medicine at the Peninsula Medical School in Exeter, said: "These fatalities are avoidable and a reminder of the need to insist on adequate training for all acupuncturists."
The number of deaths was likely to be "the tip of a larger iceberg", he added.