Similarities and Differences: Qi and Blood in TCM and Western Medicine

Doctor zhou December 18, 2020

Blood is an important component of the human body; it is a liquid connective tissue making up about 7%–8% of body weight. The blood system is the transport thoroughfare connecting organs and tissues, carrying various substances through our bodies like a courier. Our lungs use blood to deliver oxygen and expel carbon dioxide; our digestive system breaks food into small units, and blood then carries the absorbed nutrients to every organ; all the waste our bodies produce is carried by blood to the liver and kidneys, which excrete it; when our body is invaded by foreign matter or injured, immune cells are likewise carried by blood to the front lines to fend off invaders and trauma.

The red component of blood is the red blood cell, making up about 40% of total blood volume. Red blood cells contain hemoglobin, an iron-containing molecule that carries oxygen to all parts of the body. Blood also contains white blood cells, the largest of the blood cells; white blood cells (leukocytes) fight infection, though they make up only a very low proportion of total blood—about 1%. The most important component of blood is platelets: there are 150,000–350,000 platelets per microliter, making up less than 10% of total volume. Platelets and the compounds they carry have a clotting function; when our body is injured, platelets clot at the wound to repair damage and plug it, so if platelets are low, our wounds bleed without stopping. Many diseases cause platelets to drop, producing various bleeding symptoms on the body surface, such as purpura.

The remaining part of blood is plasma, a pale yellow fluid rich in sugar, fat, protein, and salt. Plasma carries red blood cells, white blood cells, platelets, and all kinds of nutrients and waste; it makes up about 50%–55% of total blood volume.

That is the basic picture of our whole blood; in fact, blood contains almost everything, and many diseases can be diagnosed by testing its components. So when we go to the hospital, the most common test is a blood draw. Because of the circulatory system's role, cancer cells can also easily spread hematogenously from one organ or tissue to another.

The human body contains many gases, but the one it needs most is oxygen; we inhale oxygen and exhale carbon dioxide. The metabolism also produces various other gases. The gases produced in the body come mainly from food fermenting in the gut; there are over 400 components in total, chiefly nitrogen, hydrogen, carbon dioxide, methane, indole, skatole, hydrogen sulfide, volatile ammonia, and volatile fatty acids.

In short, modern scientific methods can easily analyze the components of the body's "qi" and "blood." What I have described above is very brief but also quite general. Human blood contains far more than the components I have outlined; the items on a blood test report are far more complex than the few main ones I have listed, and there may yet be components scientists have not analyzed.

TCM also speaks of qi and blood. In ancient times, Chinese physicians had already noticed the existence of qi and blood and the certain relationship between them, as in the TCM saying: "Qi is the commander of blood; blood is the mother of qi." Our breathing and our blood circulation are both very easy to observe; breathing never stops for a moment, and wherever there is a wound the presence of blood is obvious. So traditional TCM's understanding of qi and blood reflects objective phenomena. But because of the limitations of the age, TCM could not possibly have analyzed the specific components of qi and blood and their corresponding functions as precisely as modern medicine.

TCM divides qi very finely, but this fine division actually lacks factual basis; most of it is imagined, and it is described especially unclearly, hard to understand, and easy to apply ambiguously in the clinic.

TCM describes the body's qi as essence qi (jingqi), original qi (yuanqi), ancestral qi (zongqi), nutritive qi (yingqi), defensive qi (weiqi), liver qi, stomach qi, spleen qi, heart qi, kidney qi, lung qi, and so on; the most important are essence qi and original qi. What TCM calls essence qi is the sum of the innately inherited qi from one's parents and the refined substances drawn later from food and water. So essence qi covers a broad range, including both the nutrients in food and a person's innate fine genes. According to TCM's view that heaven, earth, and human are one, the body's essence qi is also related to nature; in places with good air quality, the quality of the heaven-earth qi one inhales is higher, which helps raise one's spirit. We must admit that this TCM claim is quite reasonable. Original qi, for its part, is a qi rooted in the kidneys, circulating through the triple burner to the whole body, reaching inward to the zang-fu organs and outward to the skin and subcutaneous textures. The remaining kinds of qi are too numerous to explain clearly in one article.

Moreover, some TCM practitioners divide the body's qi even more finely; liver qi alone, some doctors split into more than a dozen kinds. Such division actually means little; TCM physicians who walk too far down the road of subjective speculation end up at a loss themselves, not knowing how to guide the clinic. So if we treat disease according to this doctrine, efficacy often depends on luck.

TCM also speaks of qi deficiency, qi stagnation, and qi rebellion. When qi circulates ceaselessly through the body, there is no problem; but once qi is deficient, stagnant, or rebellious, many diseases arise.

TCM also recognizes that what flows in the blood vessels is blood; it holds that "the vessels are the mansion of blood," storing blood in the vascular system. TCM holds that blood is engendered from the refined essence of food and water and from kidney essence; the spleen and stomach are the source of blood's engenderment, and the nutritive qi and fluid produced by the spleen-stomach's transportation and transformation of food essence are the main material basis for blood formation. It further holds that essence and blood can mutually engender and transform each other, and that kidney essence can transform into blood. From a modern scientific standpoint, this understanding is of course untenable. Normal human blood cells are produced in bone marrow and lymphoid tissue; the body has a hematopoietic system composed of hematopoietic organs and hematopoietic cells, the entire system that makes blood in the body, chiefly including the yolk sac, liver, spleen, kidneys, thymus, lymph nodes, and bone marrow. Hematopoietic cells all arise in the embryonic mesoderm.

According to TCM's yin-yang and five-phase theory, the heart pertains to fire and its color is red, and blood is also red, so TCM holds that blood, warmed by heart qi, transforms into a red liquid. Blood nourishes the whole body. TCM recognizes the importance of blood and qi to the human body: blood nourishes the whole body, and "Qi and blood are the spirit of a person and must be carefully nourished" (Suwen, On the Essentials of the Genuine on the Basis of the Eight Winds).

Overall, TCM's descriptions of qi and blood are not accurate by today's standards. But its descriptions of the relationship between qi and blood, and of the functions of blood and original qi, cannot be called entirely wrong. Moreover, the qi-supplementing and blood-nourishing medicinals and formulas of TCM can solve many practical problems and have their merits; they cannot be dismissed wholesale.

For example, the TCM concept of qi deficiency is closely related to modern anemia (especially low hemoglobin), while blood stasis basically corresponds to the modern pattern of static blood. So TCM's qi-supplementing herbs such as astragalus and ginseng improve blood circulation. TCM's blood-activating and stasis-resolving herbs also noticeably improve health problems caused by thrombus and excessive blood viscosity. TCM's qi stagnation, for the most part, is caused by digestive problems; after using some drugs that improve digestive function, most qi-stagnation problems can be resolved.

Of course, we cannot integrate Chinese and Western qi-blood theory with such a simple method. In fact, TCM's visceral manifestation theory and qi-blood theory are very complex; though much of it is speculative textual description, there is also much that is reasonable, requiring us to discard the coarse and select the fine.

If we understand both the Chinese and Western concepts of qi and blood, we often make unexpected gains in clinical practice.

For example, I have used Buyang Huanwu Tang effectively for a series of problems caused by hypoxia. A cerebral infarction patient may not be anemic, but because the infarction causes brain hypoxia with symptoms like dizziness and hemiplegia, Buyang Huanwu Tang can relieve them; when an anemic patient with very low hemoglobin shows TCM symptoms of qi deficiency, treating with Buyang Huanwu Tang also works well. This formula can markedly improve the body's tissue hypoxia. In my own use, I combined Chinese and Western knowledge to grasp its main indication. This more precise method of selecting formulas and medicinals benefits from the effort to integrate Chinese and Western qi-blood theory; so, from my own experience, TCM physicians studying Western medicine helps improve clinical efficacy and reduce misdiagnosis and mistreatment.

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