The Vital Substances of Chinese Medicine
In Chinese medicine, health and disease are often discussed in terms of several different substances that permeate the human body. These are often referred to as the “vital substances” as their activity affects both physical and psychological wellbeing.
This article explores the functions of these vital substances and what happens when they become imbalanced.
The Yin and Yang of the Substances
The vital substances are often categorised as being more yin or more yang in nature. Those that are more yin are denser and make up the matter of the body, while those that are more yang are lighter and tend to be responsible for function rather than form.
The vital substances are listed below, from the most yin to the most yang:
Fluids
Jing (essence)
Blood
Qi
Shen
Now, let’s look at each of these in more detail.
Fluids
In Chinese, the bodily fluids are known as jinye (津液) with jin meaning “saliva” or “sweat” and ye meaning “fluid,” “liquid,” or “juice.” These fluids can be further classified as jin, which includes light and watery fluids like saliva, sweat, and tears, and ye, which are thicker and moisten the joints, brain, and bone marrow.
These fluids are said to originate from food and drink, which are first processed by the Stomach and then the Spleen, the major digestive organs in Chinese medicine.
The Stomach breaks down food into a soupy liquid, before the Spleen separates it into “clean” and “dirty” parts. Then, the Spleen sends the clean fluids to the Lung, which circulates them around the body, and the dirty fluids to the Small Intestine for further processing.
The Small Intestine separates the fluids again, into “pure” and “impure” parts, sending the pure fluids to the Bladder and the impure fluids to the Large Intestine.
A third separation occurs in the Bladder, which sends pure fluids to the skin to form sweat, while the impure fluids are excreted as urine. Meanwhile, in the Large Intestine, some water is reabsorbed, while the remaining impure fluids are excreted as faeces.
Each of these separations requires its respective organ to function correctly, although the Spleen is often seen as having the most important role overall. The Lung and Kidney systems also have an essential role, as these organs work together to circulate fluids around the entire body.
Dysfunction of any of these organs can result in inappropriate processing of body fluids and excessive dampness or dryness in the body. This might manifest as oedema, heavy limbs, tiredness, brain fog, etc. (dampness) or dry skin, dry throat, dry cough, constipation, etc. (dryness).
Therefore, supporting the Spleen with a well-balanced diet and good eating habits is one of the best ways to maintain a healthy balance of fluids within the body. Meanwhile, keeping warm and engaging in regular moderate physical activity will assist the Lung and Kidney in their circulatory function.
Jing (Essence)
Jing (精) is usually translated as “essence.” It is a yin substance that is stored by the Kidney and is responsible for growth, development, reproduction, and ageing. It is said to follow seven-year cycles in females and eight-year cycles in males that govern the various stages of human life.
Jing can be subdivided into pre-heavenly (or prenatal) jing and post-heavenly (postnatal) jing. The former is hereditary and largely depends upon our parents' age and health at the moment of our conception. The latter is determined by our diet, lifestyle, and environment.
Although both forms of jing can significantly influence our health, only postheavenly jing is modifiable. Therefore, some people have a constitutional weakness where jing is concerned and may have to work harder to maintain their health and wellbeing.
Jing is typically associated with the Kidney, which stores pre-heavenly jing, but the Stomach and Spleen are also important as they are responsible for extracting food essences to create post-heavenly jing. Therefore, all of these organs must function well to maintain our jing reserves.
Jing deficiency can result in symptoms like slow development in children and infertility or sexual dysfunction in adults. Premature ageing is also associated with weak jing, with signs such as early greying of the hair, poor memory, hearing loss, reduced bone density, and so on.
Qi gong and tai chi are two activities that are said to be particularly beneficial for nourishing and preserving jing. In addition, we should aim to eat a balanced diet, avoid stimulants, engage in sufficient exercise and rest, and practise restraint in sexual activity.
There is some debate as to what the latter actually means, but it is generally accepted that jing is synonymous with semen, and frequent ejaculation is said to damage jing in males. In females, jing is more associated with pregnancy and childbirth, and multiple births close together are said to be depleting.
Blood
Blood, known as xue (血) in Chinese medicine, is quite different from blood in a biomedical context, and it is typically written with a capital B to distinguish the two substances.
Blood is very closely related to qi (see below), and the two are often considered to be yin and yang aspects of the same substance. Blood is responsible for nourishing qi, while qi is responsible for moving Blood around the body. It is often said that “Blood is the mother of qi, while qi is the master of Blood.”
Blood has a supportive and warming effect on the body, moistening the tissues and keeping them healthy and supple. The Blood also acts as an anchor for the shen (see below), to prevent it from floating away. Therefore, having healthy Blood is associated with not only physical but also emotional wellbeing.
Blood is primarily derived from food, and so the Stomach and Spleen are both heavily involved in its production. The Spleen also has a holding effect on Blood to ensure it stays inside the vessels.
The Liver plays a vital role in Blood health as this organ is said to store Blood and allow it to regenerate. Meanwhile, the Heart is said to govern the vessels and is responsible for Blood circulation as well as playing a crucial role in its creation. The Lung and Kidney both have lesser but equally important roles in Blood formation and circulation.
Blood deficiency can manifest as pale skin, dry skin and hair, dizziness, tiredness, anxiety, insomnia, and scanty menstruation. Blood can also be affected by excessive heat in the body, causing bleeding (such as nosebleeds) and heavy menstruation. Blood stasis is another common pattern in which Blood circulation is affected, resulting in bruising, pain, and painful and irregular menstruation.
Because Blood derives from food, eating a nourishing diet is key to keeping this substance healthy. Red meat and dark red beans, fruits, and vegetables are particularly beneficial. Healthy expression and regulation of the emotions is also essential in keeping the Blood cool and circulating freely.
Qi
Qi (气) is most often translated as “energy,” but this does not really do justice to the vast range of functions that this substance has within the body. Moreover, there are different types of qi, including original yuan qi, which is closely related to jing, nutritive ying qi, which nourishes the tissues, and defensive wei qi, which circulates the exterior of the body and protects us against harmful external factors.
Ying qi and wei qi are both considered forms of true zhen qi, which is formed from a combination of food essences, extracted by the Stomach and Spleen, air from the Lung, and yuan qi from the Kidney. Therefore, all of these organs are considered essential for healthy qi function. The Liver also plays a vital role as it is responsible for circulating qi around the body.
If qi becomes deficient, this can result in a whole range of symptoms, depending on which organs are affected. Broadly speaking, these are tiredness, weak voice, shortness of breath, spontaneous sweating, poor appetite, loose stools, and pale skin. If qi is unable to flow freely, this can cause digestive issues, pain, and emotional symptoms, such as depression and irritability. Irregular menstruation and PMS are also signs of qi stagnation.
To keep qi healthy and flowing freely, it is essential to tend to the organs listed above, paying particular attention to diet, breathing, and regular moderate exercise.
Shen
Shen (神) is usually translated as “mind” or “spirit,” although neither of these words quite sums up its true meaning. “Mind-spirit” or “consciousness” might be closer, but still feel somewhat inadequate.
The shen is said to reside in the Heart and is responsible for our sleep, emotions, and ability to think clearly. It is complemented by four other “spirits” that reside in the other organs, the zhi (志) or “willpower,” which resides in the Kidney, the yi (意), or “ideation,” which resides in the Spleen, the po (魄) or “corporeal soul,” which resides in the Lung, and the hun (魂) or “ethereal soul,” which resides in the Liver.
Healthy shen relies on healthy Blood, and therefore, the Stomach, Spleen, Liver, Kidney, and Lung are all involved alongside the Heart. If the Blood is deficient or if the Heart becomes imbalanced for some other reason, the shen can be disturbed, resulting in emotional issues, insomnia, and disturbed sleep.
Therefore, it is important to keep the Blood healthy as described above and use practices such as meditation to help regulate the Heart and the emotions.
Nourishing the Vital Substances
The vital substances are essential to our physical and mental health and must be adequately nourished in order to maintain wellbeing. By now, it should be clear that diet is a key part of this, as our food and ability to process it either directly or indirectly influence every one of the vital substances. To learn more, visit the Chinese Dietary Therapy section of this website.
Other practices, such as physical activity, rest, and meditation, are also crucial parts of the puzzle. By striving for balance in all of these areas, while avoiding excesses and harmful habits, we can significantly increase our chances of living a long and healthy life.
References:
Maciocia G (1989) The Foundations of Chinese Medicine (first edition) - Churchill Livingstone Elsevier, London
Wiseman N, Feng Y (2014) A Practical Dictionary of Chinese Medicine - Paradigm Publications, Taos, NM