Acupuncture originated as a therapeutic modality in traditional Chinese medicine.[16] Its theoretical foundation can be traced back to Neijing (“The Yellow Emperor’s Classic of Internal Medicine”), compiled between 305 and 204 BCE. A relatively complete description of meridians and acupuncture points (or acupoints) on the body can be found in Zhenjiu jiayi jing (“Numbered book on acupuncture and moxibustion”), the oldest surviving writing on acupuncture and moxibustion (the application of heat to certain points on the body) published around 260 CE. Classical acupuncture involves the insertion of needles at selected acupoints to a defined depth, followed by manipulation with physical forces, heat, or more recently, electrical stimuli.
According to traditional Chinese medicine, vital energy (“chi” or “qi” in Chinese) flows throughout the body along meridian pathways. Interruption or obstruction of qi was believed to make one vulnerable to illness. The insertion of needles at specific meridian acupoints was thought to regulate the flow of qi, thus producing therapeutic benefit.
Although the ideas of qi and meridians are inconsistent with the modern understanding of human anatomy and physiology, recent neuroscience research suggests that acupuncture may provide clinical effects by modulating the nervous system. Neurotransmitters identified in laboratory research and neuronal matrices activated or deactivated during acupuncture have been observed in functional neuroimaging (functional MRI or positron emission tomography) studies.[17] Therefore, qi and meridians can be seen as vehicles used by ancient people to explain clinical responses observed during acupuncture.[18]
In a typical acupuncture treatment, the therapist interviews the patient; performs a physical examination, including pulse and tongue appearance (regarded as windows into the patient’s hemodynamic and microcirculation status); and then arrives at a traditional Chinese medicine diagnosis, which describes syndrome patterns rather than pathologic processes. For example, a constellation of insomnia, irritability, racing thoughts, dry mouth, and hot flashes represents the “heart fire” pattern. Acupoints are then selected based on the pattern diagnosis.
Single-use, sterile stainless steel needles protected by a guide tube are used in modern acupuncture practice. Acupuncture needles are filiform and very thin (28–40 gauge), similar to or thinner than insulin needles. In the United States, acupuncture needles are classified as medical devices. In a typical treatment, acupoints are located and the sites cleaned with alcohol swabs. The needle and its guide tube are placed at each site. A gentle tap applied to the top of the needle makes it penetrate the skin. The guide tube is then removed, and the needle advanced to the desired depth in a gentle twisting and pushing movement (Figure). The therapist may decide to apply heat or electrical stimuli to the needle. Traditionally, heat stimulation is provided by attaching a burning mound of the herb Artemisia vulgaris to the needle. In modern practice, it is provided by a heat lamp. In electroacupuncture, a small electric pulse–generating device connects to pairs of acupuncture needles to deliver electrical stimulation to the acupoints, in a manner akin to transcutaneous electrical nerve stimulation (TENS).
