Studies have shown that acupuncture treatments can result in slight pain, bleeding or bruising.
These adverse reactions are only minor and transient, but they occur in roughly 10 per cent of patients so are relatively common.
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Although most patients may accept such risks as an unsurprising consequence of being pierced with needles, there are two serious adverse effects to consider.
The first is infection. There have been several documented cases of patients contracting diseases such as hepatitis.
The journal Hepatology documented how 35 out of 366 patients contracted hepatitis B from an acupuncture clinic in America.
The infection was caused by re-using needles that have not been properly sterilised, and part of the problem may be due to the Chinese tradition of storing needles in alcohol solutions, which is not sufficient to protect against hepatitis viruses.
The second is that needles might puncture a major nerve or organ.
For example, needling at the base of the skull can lead to brain damage, and there are more than 60 reported cases of punctured lungs.
Most worrying of all, there is a report of an acupuncturist inserting a needle in the chest of an Austrian patient which pierced her heart and killed her.