It has long been known to practitioners of traditional Chinese medicine that acupuncture is effective in treating the symptoms of anxiety and stress. What has been difficult for our western culture to grasp is exactly HOW this is possible.
Researchers were able to measure biological mechanisms involving an assortment of hormones that the body secretes into the bloodstream as a reaction to stress. In this controlled study of rats, they assessed blood hormone levels secreted by the hypothalamus, the pituitary gland and the adrenal gland -- together these are known as the hypothalamus pituitary adrenal (HPA) axis. They also measured a peptide involved in "fight or flight" responses, called NPY.
"The researchers discovered that stress hormones were lower in rats that had received electronic acupuncture. Results were published in the Journal of Endocrinology."