[Acupuncture for nausea: how does it work?].

Nausea, the unpleasant feeling that one is going to vomit, results from the stimulation of the Chemoreceptor Trigger Zone (CTZ) and Vomiting Center in the brain. Conventional medical therapy is not always effective, and medications often have severe adverse effects. Acupuncture is a treatment in which thin needles (diameter of 0.20-0.30 mm) are inserted into various points along the skin, according to energy channels (meridians) established thousands of years ago. The anti-emetic effects of acupuncture apparently stem from the resultant increase in hypophyseal secretion of beta-endorphins and ACTH, with subsequent inhibition of the CTZ and vomiting center. Acupuncture also affects the upper GI tract, decreasing acid secretion and repressing gastric arrhythmias. Clinical research has found this treatment modality to be effective for nausea, whether it be due to morning sickness in pregnant women, motion sickness in travellers, postoperative nausea or chemotherapy-induced nausea in cancer patients.