Qi (vital Energy) from a TCM Perspective

Western medicine places strong emphasis on the physical structures of the body, which are made up of different organic and inorganic substances, proteins, tissues and cells. These substances form the physiological basis of humans. Traditional Chinese medicine (TCM), on the other hand, views life a little differently. Instead of emphasizing discrete body components with cells being the basic building blocks, the body is seen as a whole entity with connecting parts that work together to sustain life. Some parts have more energetic properties while others have more material characteristics. The interaction between the different parts is vital to the individual's being so they are often referred to as fundamental substances. Qi (pronounced chee), blood and body fluids are the most important fundamental substances necessary for life.

The ancient Chinese people believed qi was the most fundamental entity making up the world. They thought everything in the universe resulted from the movement and change of qi. The Chinese character for "qi" is the same word used for air or gas, and it is thought to have the same properties as these substances. Qi can be interpreted as the "life energy" or "life force," which flows within us. Sometimes, it is known as the "vital energy" of the body.
In TCM theory, qi is the vital substance constituting the human body. It also refers to the physiological functions of organs and meridians. In fact, it may be difficult to find one equivalent English word or phrase that completely describes the nature of qi. Most often, qi is best defined according to its functions and properties.

The origin of Qi
Human qi comes from two main sources. The first source of qi is inherited from our parents at conception. It is known as the "innate vital substance". The second source is derived from essential substances in nature such as the air we breathe, food and water. Both the inherited and the acquired vital energies are further processed and transformed by the organs.
The kidney first sends the innate vital substance upwards where it combines with food essence derived from the spleen. It further mixes with the fresh air from the lungs where it finally forms into qi of the body.
By understanding how qi is formed, TCM has identified two important factors necessary for maintaining health. By eating a healthy diet and breathing fresh air, the body extracts their most valuable essences and uses them to help form the vital energy. Following these simple principles are the first steps towards creating a healthy balance in the body.

Functions of Qi
1. Promoting function of qi
Just as wind (highly active air) provides energy to push the sails of a boat or turn the turbine of a windmill, qi provides the active, vital energy necessary for the growth and development of the human body and to perform the physiological functions of the organs, meridians and tissues. In addition, qi promotes the formation and circulation of blood and supports the metabolism of body fluid. If there is a deficiency of qi, its promoting functions are weakened. As a result, growth and development can be affected or delayed, the organs and meridians cannot function properly and blood formation is hampered, leading to a series of health problems.
2. Warming function
In a gaseous state, air contains more kinetic heat energy than in its liquid state. Like air, qi also contains heat energy for the body. Being a heat source, qi warms the body and keeps it at a constant temperature so normal physiological functions can take place. Deficiency of qi can lead to a lowered body temperature, intolerance of cold and cold hands and feet.
3. Defending function
In TCM, one of the main causes of disease is the invasion of "Evils"."Evils" are environmental factors that lead to illness. They are classified as wind, summer heat, dampness, dryness, cold and fire. By resisting the entry of ' illness evils" into the body, qi defends against their attack and maintains healthy physiological functions. In western terms, this qi defending function acts like the immune system.
4. Consolidation and retention function
Qi consolidates and retains the body's substances and organs by holding everything in its proper place. First, qi keeps the blood flowing within the vessels and prevents it leaking out into the tissues. Secondly, qi controls and adjusts the secretion and excretion of sweat, urine and saliva, and keeps body fluids from escaping the body. Thirdly, qi consolidates and stores sperm to prevent premature ejaculation. Lastly, qi consolidates the organs and stops them from descending into a position where they cannot function properly. If qi is deficient, the consolidating function is weakened, leading to various kinds of health problems such as hemorrhage; frequent urination, premature ejaculation and stomach or kidney prolapses (where the organ sinks).
The promoting and consolidating functions work in a complementary manner. For example, qi promotes blood circulation and the distribution of body fluids, but it also controls and adjusts the secretion of fluid substances. The balance between these two functions is essential for maintaining a healthy blood circulation and water metabolism.
5. Transforming functions
Qi also possesses vaporization or " transformation" functions, which are important for the metabolism of fundamental substances. As suggested by these words, qi may "vaporize" substances in the body and transform them into essence or vital energy. For example, certain actions of qi allow food to be changed into food essence, which is in turn transformed into different types of qi and blood. Indigestible food and waste are also transformed by qi into urine and stools for excretion.
Movement of Qi
The four directions of qi movement are up, down, outward and inward. These movements are so important that once qi can no longer travel in these directions, life will come to an end.
Each organ has different specialized movements. For example, spleen qi ascends the pure part of digested food from the stomach for transformation into nutritional essence. Stomach qi, on the other hand, pushes food downwards in order to remove its impurities. Some organs, like the lungs, perform movements in all four directions. Lung qi moves in and out during breathing. However, when disseminating nutritional essence to the body, lung qi ascends and then descends when liquefying waste to be sent to the kidneys.
The different movements of qi work in a coordinated manner to maintain a harmonious balance. The ascending balances the descending movement while the outward balances the inward movement. Balanced movement is important for promoting the physiological functions of different tissues, organs and meridians. Disharmonious movement of qi leads to health problems. For example, insufficient downward movement of lung qi causes a cough. When stomach qi cannot descend nausea and vomiting occurs.

Types of Qi
Qi is further classified according to its type. The four types are inborn qi, pectoral qi, nutritive qi and protective qi.
1. Inborn qi
Inborn qi is the most original, essential and vital type found in the human body. It possesses prenatal and congenital properties. After conception, "congenital essence" (an essential vital substance inherited from parents) is stored in the kidney, the place from which inborn qi originates. Inborn qi is further nourished by "acquired essence" (food essence derived from digestion) of the spleen and stomach. After this process is complete, inborn qi is ready to travel to the entire body to exert its effects. Starting from the portion between the two kidneys, known as the "vital gate", the qi moves through the triple burner and circulates through the organs, muscles, skin and meridians providing the power source for all of life's activities.
2. Pectoral qi
Pectoral qi is stored in the chest. It is formed by combining fresh air inhaled by the lungs and food essence derived from the spleen and the stomach. Because pectoral qi concentrates in the chest, it can penetrate the blood vessels of the heart and lungs and move outward during expiration and inward during inspiration. By flowing through the respiratory tract, pectoral qi supports the breathing function of the lungs and affects how loud the voice can be. Its ability to flow through the blood vessels and the heart is important in regulating the heartbeat and supporting the circulation of other types of qi and blood. Pectoral qi also plays a role in keeping the body warm and influences the activities of the limbs.
3. Nutritive qi
Nutritive qi, as its name suggests, supplies nourishment to the body. It mainly circulates through the blood vessels with the blood. Sometimes this combination of nutritive qi and blood is referred to collectively as "nutritive blood". Nutritive qi mainly comes from food essence derived by the spleen and stomach's transformation and transportation properties. Starting from the middle burner, nutritive qi goes to the lungs where it enters the main circulation. Nutritive qi has yin properties so it can form into materials needed by other parts of the body. For example, its close relationship with blood allows it to provide some of the necessary substances needed to produce new blood. Nutritive qi also provides the needed nutrients to support the physiological functions of the organs.
4. Protective qi
Protective qi protects against evils. As previously mentioned, evils are environmental factors that lead to illness. In western terms, protective qi functions like the immune system, which helps prevent disease from occurring or spreading. Unlike nutritive qi, protective qi has yang properties, because it has more functional characteristics.
Protective qi also comes from the food essence derived by the spleen and stomach. It moves outside the blood vessels and circulates in different areas from nutritive qi. Internally, it will be distributed to the diaphragm and scattered around the chest and abdominal cavities. Externally, it moves between the skin and muscles providing protection. Protective qi not only guards against illness and disease but also regulates the sweat glands and pores and provides nourishment for the skin, hair and muscles.
Although nutritive and protective qi share the same origin, their flow directions, as previously described, are opposite to one another. By balancing their nutritive (yin) and protective (yang) functions, healthy sweating, temperature control and defence functions are maintained.

Flow chart for formation of Qi