Disambiguation: The word qi is used in many different ways in Chinese medicine, both as alone and in tandem with other terms. The idea of qi in qi-blood is not the same as the idea of qi in other contexts.
To read about qi as a standalone concept, click here
To read about qi as a part of jing, qi, and shen, click here
What it is
Enthusiasts like me have a habit of gushing that traditional Chinese medicine sees and treats the body holistically. That certainly sounds nice, but let's be honest: even though the word "holistic" has entered the mainstream, it is a fuzzy term that means a lot of different things to a lot of different people. In Chinese medicine the idea of holism is actually very clearly defined (read more here), and a big part of it comes to down to the way in which all of the zang-fu organs are connected to each other and everything else in your body via the meridians. However, the mere existence of static connections is not enough to create real linkages; what use would all the fiber-optic cables in the world be if there was no information flowing through them? Just as the hardware housing the internet is brought to life by a torrent of information and electricity, our bodies are given life by the neverending circulation of qi-blood, the substance and energy binding all your disparate parts into a singular whole.
So, if qi-blood is simply the stuff flowing through all our pipes and cables, why can't we just talk about good-old-fashioned blood without getting all fancy by adding a "qi" to the front of the word? That's where one of TCM's core concepts, yin-yang theory, comes into play. The thing is that Chinese medicine, which has deep roots in Daoism, conceives of all things in the world by looking at them from two angles at the same time. In this particular case, the two angles are substance and function; blood is the former while qi largely points to the latter.
In terms of substance, the blood half of "qi-blood" is none other than the red stuff vampires and mosquitoes so dearly covet. TCM's definition of the word also includes what we modern people might call nutrition, ie, all the important physical substances we obtain from food and drink and which the blood carries around to all your organs and tissues like a giant delivery system.
Substance and form are yin, but function is yang, and therefore it's all about action. The qi half of "qi-blood" is an idea that encompasses the things about blood that we can't necessarily see, but which we know it does. That means it includes the heat carried via your circulation to your extremities; it includes blood's very ability to move without becoming blocked up; it includes the functions associated with immune cells in your blood stream; it includes the propensity of oxygen and energy in your bloodstream to provide the basis for all your cells' metabolic processes; and it includes that which we might call "subtle energies" and/or "information," which are things that aren't much discussed in mainstream science but which those of us with certain levels of sensitivity have all felt at varying points in our lives.
As far as TCM is concerned, form without function is as useless to the human body as function without form, and thus it is that qi and blood are viewed not as two separate entities, but rather as two sides of the same very important coin.
What it does
Qi and blood work together in your body to accomplish number of different tasks, some of which won't surprise you at all, and some of which might sound a bit weird.
- Least odd-sounding of all, it's the job of blood to deliver nourishment to all parts of the body as it reaches them via the vessels. Chinese medicine holds that lustrous hair, a glowing complexion, and naturally smooth skin are outward signs of healthy blood. Conversely, people with dry, brittle hair, sallow complexions, and dry or scaly skin may very well given blood tonifying treatments.
- Much stranger-sounding is blood's second task, which is to provide the "material basis of consciousness." Fear not, this idea is not nearly as madcap as it might seem, and I explain it in detail in the section on the heart. Consciousness- and sensory-related symptoms which might be treated by tonifying blood include quite an array, running from insomnia to numbness in the extremities to palpitations to dizziness.
TCM's definition of blood isn't too hard to grasp, but things get a bit more complicated when we start talking its other half, qi, so get ready to do a bit of mental gymnastics on the next page!
The functions ascribed to qi are numerous but not all of them pertain to what qi does when it's united with blood. For simplicity/sanity's sake, we'll only look at the functions directly pertinent to circulation here.
- Supplying impetus: remember from the last page how qi-blood is a yin-yang pair? Qi is the dynamic yang half, and discussed in this context it's not a tangible thing so as it is an category including the manifold bodily process which rely not only on the materials in blood, but also the changes that a constantly-moving supply of blood is capable of promoting. Those changes range all the way from the very-micro (cell metabolism) to the sightly-less-micro (all kinds of transport hither and tither in the bloodstream) to the not-entirely-micro (the many benefits that come from having a well-regulated circulatory system, including general health and the feeling of well-being described in the heart section). In a word, blood is the material, while qi alludes its activity, without which we could not live.
- TCM holds that the qi in your blood key to making sure that your body is warm enough and that its warmth is distributed evenly, an idea not unlike modern medicine's description of blood's role in thermoregulation (https://en.wikipedia.org/wiki/Blood#Thermoregulation). Therefore, if you've got cold hands and feet, a TCM doctor might help your circulation by tonifying your qi.
- Finally, the word qi is sometimes used in TCM to succinctly pack very complex ideas about the body's immune capabalities into a single Chinese character. Long story short, a big part of the reason that blood needs to "carry" qi everywhere is to prevent all kinds of illnesses. This sense of the word qi for many practitioners and scholars points to a kind of "energy," something intangible and yet real, a bit like an electric field. Science agrees, the human body does produce electromagnetic fields, but their connection to immunology is not yet widely explored. To speak in more familiar terms, we can once again understand the word qi as a reference to functions, in this case the functions of the many immune cells traveling in the bloodstream as well as the bloodstream's important job of clearing waste products from the body. In other words, the qi "carried" in your blood is on constant, active duty making sure you don't get sick. If your qi is healthy, then you will be, too.
Where does it come from?
Everything I'm about to write below is pretty complicated, so let's start this page with a practical statement, so you can skim the rest: the quality of your qi-blood is primarily related to your food, underlining the importance of having a healthy, balanced diet. Furthermore, because creating qi-blood is a holistic, whole-body affair, you can see why having a balanced lifestyle that promotes your general health is so important.
Now for the tough stuff: the unity of substance and function we call qi-blood is a product of your entire zang-fu organ system. There's a phrase in Chinese medicine, "blood is governed by the heart, stored in the liver, held together by the spleen, and rooted in the kidneys." That's practically Chinese! What's it really mean? Well, it means you've got to read through all those underlined links in order to know from whence Chinese medicine traces the origins of qi-blood!
Because I'm so nice, I've written a synopsis, but remember, I'm using TCM ideas, which are not the same as modern science's: The basic constituent of blood is the nutrients in your food. When food and drink enter your stomach, spleen yang steps up to the plate remove the "essences" contained in what you eat from the stomach and intestines and then sends them up to your lungs where the air mixes with blood, imbuing it with qi and, of course, oxygen. From the lungs the blood enters the heart, where it obtains "heart fire," a metaphor for the heart's yang function of giving blood dynamism and movement; in other words, the heartbeat gets blood moving. From there qi-blood is able to travel all around the body, doing the jobs described in the above pages. Just to be thorough, we have to remember that as blood is "created" it is also imbued with "essences" stored by your kidneys. Finally the liver's energetics directly influence both qi-blood's motion and quantity, making sure it neither becomes stagnant nor "overactive," which can lead to bleeding disorders. Whew!
Now, given that we know red blood cell production takes place mostly in the bone marrow, does that mean that everything I wrote above is medieval quackery that should be thrown in the waste bin? Well, not so fast. First of all, there's a lot more comprising blood than red blood cells--plasma, which comprises 55% of your blood, is a liquid whose creation is governed by processes that TCM ascribes particularly to the kidneys and spleen. Secondly, even though the idea certainly seems foreign to us, TCM has always considered the bones as "part" of the kidneys. Lastly, remember: qi-blood is a holistic idea that views substance and function as one. The physical substance we call blood is only half of the equation. To understand the dynamic second half, qi, we must look at its actions and movements, a consideration which necessarily takes us all around the body!