Acupuncture is one of the oldest, most commonly used medical procedures in the world. Originating in China more than 2,000 years ago, acupuncture became widely known in the United States in 1971 when New York Times reporter James Reston wrote about how doctors in Beijing, China, used needles to ease his abdominal pain after surgery. Research shows that acupuncture is beneficial in treating a variety of health conditions.
In the past two decades, acupuncture has grown in popularity in the United States. In 1993, the U.S. Food and Drug Administration (FDA) estimated that Americans made 9 to 12 million visits per year to acupuncture practitioners and spent as much as $500 million on acupuncture treatments.1 In 1995, an estimated 10,000 nationally certified acupuncturists were practicing in the United States.
Currently, an estimated one-third of certified acupuncturists in the United States are medical doctors.
Traditional Chinese medicine theorizes that the more than 2,000 acupuncture points on the human body connect with 12 main and 8 secondary pathways, called meridians. Chinese medicine practitioners believe these meridians conduct energy, or qi, between the surface of the body and internal organs.
Qi regulates spiritual, emotional, mental, and physical balance. Qi is influenced by the opposing forces of yin and yang. According to traditional Chinese medicine, when yin and yang are balanced, they work together with the natural flow of qi to help the body achieve and maintain health. Acupuncture is believed to balance yin and yang, keep the normal flow of energy unblocked, and restore health to the body and mind.
Traditional Chinese medicine practices (including acupuncture, herbs, diet, massage, and meditative physical exercises) all are intended to improve the flow of qi.
Western scientists have found meridians hard to identify because meridians do not directly correspond to nerve or blood circulation pathways. Some researchers believe that meridians are located throughout the body’s connective tissue; others do not believe that qi exists at all. Such differences of opinion have made acupuncture a source of scientific controversy.
Mechanisms of Action
Several processes have been proposed to explain acupuncture’s effects, primarily those on pain. Acupuncture points are believed to stimulate the central nervous system (the brain and spinal cord) to release chemicals into the muscles, spinal cord, and brain. These chemicals either change the experience of pain or release other chemicals, such as hormones, that influence the body’s self-regulating systems. The biochemical changes may stimulate the body’s natural healing abilities and promote physical and emotional well-being.
There are three main mechanisms:
1. Conduction of electromagnetic signals: Western scientists have found evidence that acupuncture points are strategic conductors of electromagnetic signals. Stimulating points along these pathways through acupuncture enables electromagnetic signals to be relayed at a greater rate than under normal conditions. These signals may start the flow of pain-killing biochemicals, such as endorphins, and of immune system cells to specific sites in the body that are injured or vulnerable to disease.
2. Activation of opioid systems: Research has found that several types of opioids may be released into the central nervous system during acupuncture treatment, thereby reducing pain.
3. Changes in brain chemistry, sensation, and involuntary body functions: Studies have shown that acupuncture may alter brain chemistry by changing the release of neurotransmitters and neurohormones in a good way. Acupuncture also has been documented to affect the parts of the central nervous system related to sensation and involuntary body functions, such as immune reactions and processes whereby a person’s blood pressure, blood flow, and body temperature are regulated.
Revision date: July 8, 2011
Last revised: by David A. Scott, M.D.