This article is from the Alternative Medicine Therapies guide.
According to the principles of TCM, qi flows through the body via 14 primary meridians or channels. To strengthen the flow of qi, or remove blockages in the meridians, an acupuncturist inserts a number of tiny, sterile, flexible needles just under the skin at certain specific points (called acupoints) along the channels. There are thousands of acupoints along the meridians, which are associated with specific internal organs or organ systems. If you are suffering from nausea, for example, needles might be inserted into acupoints on your wrist, while a vision problem might be treated with needles in the foot. (Ear, scalp, and hand points are also commonly used by some practitioners.) TCM proponents believe that acupuncture stimulates the body's internal regulatory system and nurtures a natural healing response.
Although Western science has neither proven nor accepted the notion of qi, a large body of evidence is accumulating indicating that acupuncture leads to real physiologic changes in the body. Numerous studies have shown, for example, that inserting needles into the skin stimulates nerves in the underlying muscles. This stimulation, researchers feel, sends impulses up the spinal cord to a relatively primitive part of the brain known as the limbic system, as well as to the mid-brain and the pituitary gland. Somehow that signaling leads to the release of endorphins and mono-amines, chemicals that block pain signals in the spinal chord and brain.
In one study, researchers using brain scans discovered that acupuncture can alter blood circulation within the brain, increasing the blood flow to the thalamus, the area of the brain that relays pain and other sensory messages.
Hundreds of studies are now ongoing in the U.S. and elsewhere seeking to prove the usefulness of acupuncture for various ailments.