What is the anatomical basis of acupuncture?

Acupuncture is an important treatment modality that is often used in an integrative medicine and functional medicine approach to health. Compared with pharmacologic and many other types of conventional medical interventions, it is relatively much better tolerated, with a long history of real-world therapeutic benefits reported by patients.

One important caveat in the attempt to understand how acupuncture works from the conventional Western medicine perspective is that we are dealing with two very different medical paradigms of looking at the human body—to wit, classical Chinese medicine and Western allopathic medicine. The universal guiding force and organizing energy, or Qi (pronounced “chee”), that lies at the foundation of classical Chinese medicine (and other holistic systems of healing such as Ayurveda) is simply not considered in the Western allopathic medicine paradigm. (See our Acupuncture Overview page for more information.) So, to explain how acupuncture works without incorporating the concept of Qi makes any researcher’s attempt to understand the mechanisms of action behind acupuncture treatments somewhat challenging. Nevertheless, the knowledge gained so far continues to inspire painstaking research to advance our understanding of acupuncture from the Western scientific perspective.

In this blog, we explore the anatomical basis of acupuncture. What body structures are actually engaged during acupuncture treatments?

Acupuncture points and meridians

Acupuncture meridians throughout the body form a network of channels through which Qi flows. Acupuncture points are located along these meridians, which connect the more superficial parts of the body with the inner parts and organs. During acupuncture treatments, needling at acupuncture points enables access to this network of interconnected meridians, organ systems, and various parts of the body. We know for certain that the network of meridians is distinct from blood vessels and nerves.

How has scientific research allowed us to better understand what is the anatomical basis of acupuncture points and meridians?

Many theories have been put forward, but some of the best evidence to date suggest that connective tissue planes, in the form of an extensive network of fascia, could be the anatomical basis for acupuncture points and meridians. What is fascia? To understand it, let’s very briefly go over some basics of anatomy.

Connective tissue is a catchall name for a type of fundamental tissue found throughout the body that connects, protects, and supports all of the body’s different parts. Examples of connective tissue include bones, cartilage, body fat, and even blood. Fascia is a thin band of fibrous connective tissue that surrounds muscles, organs, nerves, blood vessels, and almost everything else in the body. Fascia separates the muscles and holds them together. It provides a smooth surface for the muscles, joints, and organs to slide against each other. It is literally everywhere, serving as a continuous network of structure and support throughout the body.

Doctors don’t usually talk about the fascia in their day-to-day patient care except in specific clinical situations, such as plantar fasciitis and hernias. Surgeons perform fasciotomies (cutting open of fascia) to treat compartment syndromes, which may happen acutely after a significant trauma, particularly involving bone fractures, when pressure rapidly builds up in muscle compartments, which are surrounded by unyielding fascia, cutting off the blood supply. A timely fasciotomy decompresses the compartments and prevents potentially serious consequences such as loss of limb.

A remarkable body-wide network

Acupuncture meridians tend to be located along planes of fascia between muscles, or between a muscle and bone or tendon. In her research, Dr. Helene Langevin, who was a former Director of the National Center for Complementary and Integrative Health (NCCIH) at the National Institutes of Health, investigated the hypothesis that acupuncture points are preferentially located over planes of fascia (1). She and her team marked the locations of all acupuncture points and meridians in a series of gross anatomical sections through the human arm. They found that, overall, more than 80% of acupuncture points coincided with planes of fascia between muscles or within muscles (for example, between heads of the biceps muscle). Some acupuncture points also appeared to be located at the intersection of two or more planes of fascia. Where the meridians intersected the anatomical cross-sections, 50% of those intersections also coincided with planes of fascia.

Dr. Langevin’s team calculated the probability that such an observed coincidence between acupuncture points and meridians with planes of fascia could simply be due to chance, and found it to be less than 1/10 of 1%. In other words, if acupuncture points and meridians are not truly located in planes of fascia, then it would be highly unlikely for her team to have observed the findings that they did. Research by others, using 3D reconstructions of computed tomography (CT) and magnetic resonance imaging (MRI) of living human bodies, also found that the visualized patterns of fascia appear similar in form and distribution to the acupuncture meridians.

As we mentioned above, acupuncture meridians form a vast network throughout the body, through which metabolic and energy signals flow. Similarly, fascia envelopes all muscles, bones, tendons, organs, nerves, blood vessels, lymphatics, and more. Experts have proposed a more modern view of fascia as a system (rather than simply a tissue or organ) of “continuous, body-wide multiscale network” (2). They also suggest referring to the tiny spaces within the fascia itself as the “fascial interstitium.” The fascial interstitium contains hyaluronic acid, a gooey substance that has a unique property of binding water and serving as a medium through which signaling molecules (such as cytokines, chemokines, and growth factors) can flow.

Fascia contains a dense array of receptors that respond to stretch, pressure, and vibration (3), similar to the types of manipulation that may be done through acupuncture needles. In other tissues, it is well established that such mechanical stimuli are converted into biochemical signals that then influence gene expression, protein synthesis, and the behavior of cells, but how such a process works in the fascial network needs further research.

With this modern view of fascia, the structure and function of fascia make it quite a compelling candidate as the anatomical basis of acupuncture meridians. Fascia represents a continuous structural network throughout the body, and the fascial interstitium (the tiny spaces within fascia itself) is a body-wide network through which water and signaling molecules can flow. What’s more, the fascial interstitium is in uniform structural continuity throughout the body with the interstitium surrounding the smallest blood vessels (capillaries) and the interstitium (spaces) between cells. In other words, the signaling “channel” furnished by the fascial interstitium is a remarkable continuous network that permeates all levels of the body, from muscles and organs down to the smallest capillaries and even the spaces between cells. This evolving understanding of fascia helps us to better integrate the science of fascia with acupuncture points and meridians.

Therefore, when an acupuncture needle stimulates the connective tissue within this fascial network, it has the potential to transmit a form of signaling across the network of fascia to even distant parts of the body. The signaling could be mechanical, bioelectrical, or biochemical (1), across this tapestry of closely interconnected fascia throughout the body. This model of understanding acupuncture points and meridians would explain why, for example, an acupuncture needle inserted in the foot is part of a very effective treatment strategy for headaches.

To use an analogy proposed by Dr. Langevin, we can think of acupuncture points as sites of convergence in a network of connective tissue permeating the entire body, just like highway intersections in a network of primary and secondary roads (1). Needling a true acupuncture point accurately is like needling a major “highway intersection”—it can produce a powerful effect. In contrast, needling a point without accuracy or needling a “sham” or control point, as done in acupuncture research, is like needling a “secondary road”—it may still have some effect but not as powerful as we would like it to be.

“Obtaining Qi” during acupuncture treatments

During acupuncture treatments, the skillful manipulation of acupuncture needles results in a reaction known as De Qi, or “obtaining Qi,” which can be felt by the patient, the acupuncturist, or both, at the site of needling. The patient feels it as various needling sensations, while the acupuncturist feels it as a tug or grasp on the needle, described in ancient Chinese texts as “like a fish biting on a fish line.” The De Qi phenomenon is thought to represent a successful connection between the needle and the Qi flow within the meridian network, which in turn provides therapeutic access to organs and other areas of the body. Achieving the De Qi reaction, therefore, is essential to the therapeutic effect of acupuncture treatments. A skilled acupuncturist can readily discern whether the De Qi reaction is achieved or not during needling—that is, whether the Qi has arrived at the needle.

Is the De Qi reaction at acupuncture points a reproducible phenomenon? The research by Dr. Langevin showed that the needle grasp characteristic of the De Qi phenomenon can be measured using a computerized acupuncture-needling instrument as the force necessary to pull the acupuncture needle out of the skin (pullout force). She and her research team found that needle manipulation indeed increases the pullout force. In a study of 60 healthy human volunteers, they measured pullout force at actual acupuncture points and control points. Even though needle manipulation increased the pullout force at control points as well as acupuncture points, they found that the pullout force was 18% greater at actual acupuncture points than control points (4). In other words, needle grasp is enhanced at acupuncture points.

What’s happening in the body when the De Qi reaction is achieved? Dr. Langevin’s research further showed that the needle grasp is not a result of muscle contraction but rather a tight mechanical coupling between the needle and connective tissue surrounding the needle. Integrating this knowledge with the modern view of fascia we just discussed above, we can envision that a greater mechanical coupling achieved by accurate needling of acupuncture points could translate into greater stimulation of the receptors within fascia, which in turn could be converted into further mechanical signaling, bioelectrical signaling, and/or biochemical signaling transmitted through the fascial network.

Fascia contains collagen type I fibrils (tiny fibers made up of the protein, collagen), which possess inherent piezoelectric properties—meaning that they can convert a mechanical stress into electricity (5). Piezoelectricity plays a significant role in tissue repair and tissue regeneration. For example, natural bone possesses inherent piezoelectric properties, and mechanical stress on the bone powers up the piezoelectricity, which induces bone repair and regeneration (6). Fascia also contains a dense neural network that conducts conventional bioelectrical signals (7). During acupuncture treatments, the ability to access fascia through needling and activate piezoelectricity could provide one explanation as to why acupuncture has such a tremendous potential to promote tissue repair and regeneration.

The nature of scientific “models”

Let’s now take a step back and reflect on what we have just discussed up to this point.

In order to understand nature, physicists painstakingly come up with models that can explain the observable universe—models such as general relativity, quantum mechanics, and string theory. Different models exist because each one may excel in explaining certain aspects of nature better than another. Western allopathic medicine is also one model of understanding the human body, while classical Chinese medicine is another. Each excels in explaining the inner workings of the human body in its unique ways, but an integration of the two would likely provide far greater insights. To view acupuncture points and meridians as a network of fascia is simply to use another model to help us better understand how acupuncture works in the human body.

To explain the anatomical basis of acupuncture using the Western medicine model, at least at the present, is like trying to create an oil painting using only colored pencils. The success of the endeavor is unattainable without bringing in more supplies that can do the job. In the same way, without expanding the current scope of understanding within the Western medicine model, it may be impossible to fully understand or describe how acupuncture works, using the current vocabulary of Western medicine.

A sketch awaiting its colors

With this in mind, let’s briefly acknowledge that there are other models, based on Western medicine, that try to explain what acupuncture points and meridians are. Some of these examples include considering meridians as neural pathways or the space surrounding blooding vessels. Out of all currently available models, the fascial network model does a much better job at providing an anatomical basis for acupuncture points and meridians, but it is not perfect. As inevitably happens with all scientific models, progress will result in tweaking of the model or a new model that can offer a better understanding.  

There is an important aspect of acupuncture that is currently not addressed by the fascia network model. Namely, different acupuncture points and meridians have their specific functions, and the skillful and mindful design of an acupuncture strategy targeting specific points can make the difference between a successful or unsuccessful outcome. Some experts have hypothesized that structures of fascia help create distinct, compartmentalized environments where specialized functions can occur in each, while still making it possible for system-wide integration, but there is still no definitive proof of this hypothetical organizational principle (3). As it currently stands, the fascial network model of acupuncture does not explain how stimulation of specific acupuncture points and meridians carries specific signals to the targeted areas of the body. What is the anatomical and physiological basis for such an organizing force that masterminds how signaling is carried to specific parts of the body? To answer such a question, the Thalamic Neuron Theory, proposed by the highly respected acupuncture physician-educator, Dr. T. N. Lee, offers a deeply insightful theoretical framework for how acupuncture and Qi work from the Western medicine perspective (8). The sophistication of this model is beyond the scope of the current blog, but we may discuss it in a future blog.

Another mystery surrounding how acupuncture works remains. Specifically, the fascial network model does not explain how the body’s Qi may be affected by the Qi of the environment (including, for example, the Qi of the acupuncture practitioner)—a concept very fundamental to classical Chinese medicine and acupuncture.

When Professor Ming Qing Zhu, a renowned acupuncture expert who valued the importance of the practitioner’s Qi, treated countless stroke victims within hours of the stroke, his success rate was very high in achieving no residual neurological deficits in his patients (such as limb paralysis). To foster improved therapeutic efficacy in his acupuncture pupils, Professor Zhu taught that it is important for the acupuncture practitioner to cultivate their own Qi by cultivating their mind, minimizing desires, and practicing basic virtues of humanity such as compassion, righteousness, sincerity, and humility.

Of course, many research design challenges come to mind when it comes to studying whether and how an acupuncturist’s Qi may affect treatment success or not. Certainly, more research is needed to better understand “bioelectromagnetic and subtle energy medicine” and biofield therapies (9, 10). For now, the mystery of how Qi is organized within the body and harmonized between the microcosm of the body and that of the greater environment continues to inspire.

A human being is a part of the whole, called by us the Universe, a part limited in time and space. He experiences himself, his thoughts and feelings as something separated from the rest, a kind of optical delusion of his consciousness. This delusion is a kind of prison for us, restricting us to our personal desires and to affection for a few persons nearest to us. Our task must be to free ourselves from this prison by widening our circles of compassion to embrace all living creatures and the whole of nature in its beauty. Nobody is able to achieve this completely, but the striving for such achievement is in itself a part of the liberation and of a foundation for inner security.

                                                                                                            Albert Einstein (10)

References

1. Langevin HM, Yandow JA. Relationship of acupuncture points and meridians to connective tissue planes. Anat Rec. 2002;269(6):257-65.

2. Stecco C, Pratt R, Nemetz LD, Schleip R, Stecco A, Theise ND. Towards a comprehensive definition of the human fascial system. J Anat. 2025;246(6):1084-98.

3. Ferguson JC. Fascia Reimagined: A Proposed Mechanometabolic Framework for Understanding Connective Tissue Organization. Clin Anat. 2025.

4. Langevin HM, Churchill DL, Fox JR, Badger GJ, Garra BS, Krag MH. Biomechanical response to acupuncture needling in humans. J Appl Physiol (1985). 2001;91(6):2471-8.

5. Harnagea C, Vallieres M, Pfeffer CP, Wu D, Olsen BR, Pignolet A, et al. Two-dimensional nanoscale structural and functional imaging in individual collagen type I fibrils. Biophys J. 2010;98(12):3070-7.

6. Khare D, Basu B, Dubey AK. Electrical stimulation and piezoelectric biomaterials for bone tissue engineering applications. Biomaterials. 2020;258:120280.

7. Fede C, Petrelli L, Guidolin D, Porzionato A, Pirri C, Fan C, et al. Evidence of a new hidden neural network into deep fasciae. Sci Rep. 2021;11(1):12623.

8. Lee TN. Thalamic neuron theory: meridians=DNA. The genetic and embryological basis of traditional Chinese medicine including acupuncture. Med Hypotheses. 2002;59(5):504-21.

9. Jain S, Hammerschlag R, Mills P, Cohen L, Krieger R, Vieten C, et al. Clinical Studies of Biofield Therapies: Summary, Methodological Challenges, and Recommendations. Glob Adv Health Med. 2015;4(Suppl):58-66.

10. Rosch PJ. Bioelectromagnetic and subtle energy medicine: the interface between mind and matter. Ann N Y Acad Sci. 2009;1172:297-311.