The true foundation of TCM is Qi, which is loosely translated as vital energy. In TCM, Qi is considered to be the force that animates and informs all things. In the human body, Qi flows through meridians, or energy pathways. Twelve major meridians run through the body, and it is over this network that Qi travels through the body and that the body’s various organs send messages to one another. For this reason, keeping the meridians clear is imperative for the body’s self-regulating actions to occur. Through proper training, people can develop the sensitivity to feel the flow of Qi.

While it is often described in the West as energy, or vital energy, the term Qi carries a deeper meaning. Qi has two aspects: one is energy, power, or force; the other is conscious intelligence or information. Each Organ System carries its own unique Qi, which allows it to perform its unique functions; both physical (which Western medicine can describe) and energetic (which Eastern medicine can identify). This energetic function also includes an Organ System’s relationship with other Organs. (Organ is here capitalized to distinguish the TCM concept of an Organ System and its functions from the Western concept of the physical organ.) TCM frequently references several major Qi, or energy function, problems. One is an overall “Qi deficiency,” which is often described in Western medical terms as chronic fatigue syndrome (CFS). TCM also has the knowledge and ability to pinpoint which Organs have an energy deficiency.

Another major condition is described as “Qi stagnation,” which means energy and information cannot move smoothly to or from its appropriate location. For example, TCM considers pain, headache and stomachache the result of Qi stagnation. In TCM theory, blood and Qi are inseparable. Blood is the “mother” of Qi; it carries Qi and also provides nutrients for its movement. In turn, Qi is the “commander” of the blood. This means that Qi is the force that makes blood flow throughout the body and provides the intelligence that guides it to the places where it needs to be. Blood and Qi also affect one another and have the dynamic ability to transfer various properties back and forth. For example, after labor and delivery, a woman may develop a fever. TCM understands this fever to be related to blood loss, not normally an infection. Losing too much blood causes an overall Qi deficiency. When there is a Qi deficiency, the body cannot function properly and therefore presents with a fever.

Meridians, or channels, are invisible pathways through which Qi flows that form an energy network that connects all parts of the body, and the body to the universe. TCM understands that our body has twelve major meridians. Each one is related to a specific Organ System. The meridian network links meridians with each other and connects all body structures; skin, tendons, bone, internal organs, cells, atoms. TCM also understands that meridians connect the interior with exterior and the upper body with the lower body. This interlinked, animating network through which Qi flows freely makes the body an organic whole. The meridian network is like a system of highways, roads and streets that links major cities. The highways (meridians) and the cities (organs) make up an entire energy map (the body). It is through this system of roadways that energy (Qi) runs. For example, if a city’s internal streets are blocked with traffic, eventually this situation will cause a problem with the highways leading into this city. If the traffic condition worsens, even the cities linked by the major highways will experience a problem. Or, two cities may be fine and traffic may be flowing smoothly within their areas. Yet, if there is an accident and traffic builds up on one of the roads linking the cities, eventually one or both of these cities will find themselves affected by traffic congestion. This analogy offers a way to understand how blockages in meridians can cause problems in organs.

Meridians form a powerful information system within which each Organ also forms its own data system. In addition to transmitting Qi, meridians also transmit actual information to and among the Organ Systems. It is through the meridians and the flow of Qi that the various parts of the body communicate with each other faster than the speed of light. Interestingly, meridians are also sensitive to time and place. They reflect and respond to the changing energy of the seasons, the time of day and the climate of a particular place. TCM understands that when the meridian system functions well, the body (including its mind, spirit and emotions) is healthy and maintains homeostasis, a dynamic condition of internal harmony where yin and yang energies operate seamlessly.

The ancient medical text Nei Jing states: “The function of the channel (meridian) is to transport the Qi and blood and circulate yin and yang to nourish the body.” Because meridians respond to and carry stimulation as well as transmit information, they have the ability to bring healing energy to local, as well as distant, parts of the body. This can create physiological and other changes as Qi circulates. It is this function that makes acupuncture and acupressure work: at specific points along the meridian, the flow of Qi can be enhanced or modified either with needles or with the pressure of the finger or the hands. The energy practice of Qigong, with its postures and movements, also affects the flow of Qi.

The energy pathways and the Organ Systems they link provide TCM with a framework for identifying the root cause of health problems and the diagnoses to heal them. Meridians work by regulating the energy functions of the body and keeping it in harmony. If a dysfunction occurs, acupuncture or other therapy can stimulate the relevant meridian(s) to help bring an affected Organ back into balance. If Qi stagnates for too long in any meridian, it can become blocked and eventually turn into matter, setting the stage for conditions that can create a physical mass. Dysfunctional meridians can also become susceptible to external pathogenic factors that can migrate to Organs along the route of the affected meridian.

TCM understands that everything is composed of two complementary energies; one energy is yin and the other is yang. They are never separate; one cannot exist without the other. This is the yin/yang principle of interconnectedness and interdependence; it is not oppositional. The intertwined relationship is reflected in the classic black and white yin/yang symbol. No matter how you might try to divide this circle in half, the two sections will always contain both energies. The energies themselves are indivisible. From the TCM perspective, this is Universal law at its simplest and deepest.

The Theory of Yin and Yang contains no absolutes. The designation of something as yin or yang is always relative to, or in comparison with, some other thing. For example, the sun and daytime are considered to be yang in relation to the moon and the night, which are yin. However, early morning is yang in comparison to late afternoon, which is more yin.

According to the Theory of Yin and Yang, male is yang; female is yin. Everything in the body is also under the control of the binary system of yin and yang. Because yin and yang have an inseparable relationship, if there is a problem with one, the other will definitely be affected. Ideally, yin and yang should always remain in harmony, not just in balance. Understanding harmony is an important aspect of understanding TCM. Often, in Western understanding of Complementary and Alternative Medicine (CAM), the term “balance” is described as the desired state, however, in TCM, “harmony” is the ultimate goal. Although the words “balance” and “harmony” are sometimes used interchangeably, in TCM theory they are quite different: balance is merely the first step toward harmony.

Two things can be balanced; they can be of equal proportion or have equal weight, and yet still be separate. Balance has to do with the relationship between two separate entities: for instance, the relationship between the Heart and Kidney. First, a relationship must be in balance; the next step is to achieve harmony. When two things are in harmony, their energies are not just equally proportioned but blended together into a seamless whole. When two elements exist in harmony, there is an ongoing, unconscious dance between them that happens naturally. When one predominates, the other recedes; this is homeostasis, internal harmony that is a dynamic condition. In a healthy system, harmony happens naturally within the body itself, and between the body and external forces of Nature and the Universe.

So, when nature’s Qi undergoes change as it does seasonally, a person’s internal Qi will respond automatically. If, for any reason, it can’t make a smooth transition to the energy of the next season, TCM understands that illness will result. In Western medicine, this lack of harmony can be seen in patients with hot flashes. Those who suffer from this condition during the day have a yang Qi or energy deficiency; those who suffer nightly hot flashes are experiencing a yin Qi deficiency. If a woman experiences hot flashes at both times, then both energies are deficient and must be strengthened.

TCM believes that the human body is a microcosm of the Universal macrocosm. Therefore, humans must follow the laws of the Universe to achieve harmony and total health. The Yin/Yang and Five-Element theories are actually observations and descriptions of Universal law, not concepts created by man. In ancient times, practitioners of TCM discovered these complex sets of interrelationships that exist on deep energetic levels below the material surface. Over time, these insights developed into a unified body of wisdom and knowledge (TCM theories) and were applied to a way of life and to healing the human body. Even today TCM practitioners use these essential theories to understand, diagnose and treat health problems.

The Five-Element Theory is the bedrock of TCM. It evolved as a way of naming and systematizing patterns of perceived related phenomena, ranging from something as tangible as the weather to more rarified realms such as emotion and capacities of character, into five major groups named for the universal elements: Wood, Fire, Earth, Metal and Water. The Five-Element Theory states that the five major Organ Systems (Liver/Gallbladder, Heart/Small Intestine, Spleen/Stomach, Lung/Large Intestine, and Kidney/Urinary Bladder) are each related to a particular element and therefore to a broad category of correspondences or classifications: from a season of the year to a time of day, to particular colors and foods, etc. Both the Yin/Yang Theory and the Five-Element Theory reflect the entire Universal law in one complete, comprehensive system of related categories.

TCM does not consider the Five Elements themselves to be inert substances. They are fundamental energies alive in nature and always in motion. The Five-Element Theory encompasses two dynamic relationships, generation and control, that explain how the five major Organ Systems are interconnected. Each element generates, or gives energy to, another. These element pairs are known as mother and child. Each element also restrains or controls another. The proper amount of control keeps all the elements in proportion. With control, one Organ System acts as a feedback loop for its opposite pair as well as its partner Organ to keep them functioning smoothly: neither excessively nor deficiently, neither too strongly nor too weakly. These dynamic interactions enable all the Organ Systems to work in one harmonious, greater system. If their relationships are good, a state of wellness prevails; if any of the relationships become unbalanced, health problems result.

The Five-Element Theory gives a skilled TCM practitioner a range of options for addressing health problems. For instance, when a patient presents with skin problems, the TCM practitioner understands that the Organ System of the Lung and Large Intestine are involved because the skin is the “tissue” of the Lung, according to the Five Elements. Therefore, he or she can decide to heal one or both Organs to treat the root cause, not just the symptom of the skin problem.