What is Qi in Chinese medicine?
1. The Concept of
Qi
What is meant by Qi? The concept of Qi is based on the ancient Chinese
initial understanding of natural phenomena. That is, Qi is the most basic substance
of which the world is comprised. Everything in the universe results from the movements
and changes of Qi. This concept was introduced into TCM and became one of its
characteristics. After a comprehensive survey of the statements on Qi in TCM documents,
we have come to the conclusion that the meaning of Qi in TCM has two aspects.
One refers to the vital substances comprising the human body and maintaining its
life activities, such as the Qi of water and food (food essence), the Qi of breathing
(breathing nutrients) and so on. The other refers to the physiological functions
of viscera and bowels, channels and collaterals, such as the Qi of the heart,
the lung, the spleen and the stomach and so on. The Qi here referred to, is specifically
the physiological functions of these viscera and bowels.
2. The Formation of
Qi
The Qi in the human body is different in classification and formation. But,
generally speaking, it has no more than two sources. One is the innate vital substance
one inherits from one's parents before birth. The other is the food essence and
fresh air one receives from air, water and food in the natural world. The materials
obtained in the two ways above have to be processed and transformed by the viscera
and bowels before becoming the Qi of the human body. The process for Qi to be
formed is as follows The innate vital substance acted on by the kidney comes out
of the gate of life (the portion between the two kidneys) and goes up to the middle
warmer. There it combines with the food essence coming from the spleen and continues
upwards until it combines with the fresh air inhaled by the lung. Finally it turns
into Qi. It is easy to see from the above that the Qi of the human body is formed
through the joint work of the kidney, the spleen, the stomach and the lung in
combining the innate vital substance taken from one's parents, the food essence
received from water and food, and the fresh air obtained from nature.
3. The
Functions of Qi
Different kinds of Qi have different functions. Generally speaking,
they can be summarized as follows:
1) Promoting Action
Qi is a sort of essence
full of vitality. It can help activate the growth and development of the human
body, promote the physiological functions of each viscus, bowel, channel, collateral,
tissue and organ and speed up the formation and circulation of blood and the metabolism
of body fluid as well. For example, if the above functions are weakened as a result
of the deficiency of Qi (vital energy), the following will occur: late and slow
growth and development of the human body or senilism; weakened functions of viscera
and bowels, channels and collaterals, tissues and other organs; insufficient blood
formation or stagnation in blood vessels; and disturbance in the metabolism of
body fluid.
2) Warming Action
Nan Jing (Classic on Medical Problems) says:
"Qi has a warming action." Qi is the main source of the heat needed
by the human body. The body keeps its constant temperature mainly through the
warming action of its Qi. A deficiency of Qi can cause lowered body temperature,
intolerance to cold and cold limbs.
3) Defending Action
The defending action
of Qi is shown in two aspects. One is to guard the surface of the skin against
the exopathogen. The other is to combat the invading exopathogen so as to ward
it off. When the defending function of Qi is normal, the exopathogen has difficulty
in invading the body, even though it may obtain entry, it is not certain to cause
any disease. If it does cause a disease, this disease is easy to cure. When the
defending function of Qi becomes weaker, when the ability of the human body to
fight the exopathogen is lowered, the body is easily invaded and diseases are
caused. And what is more, these diseases are hard to cure.
4) Consolidating
and Governing Action
By "consolidating and governing action", we
mean that Qi has the ability to command, control and consolidate the liquid substances
and organs in the abdominal cavity. This is done by:
a. Keeping blood flowing
within, not extravasating out of; the vessels;
b. Controlling and adjusting
the secretion and excretion of sweat, urine and saliva, and preventing the body
fluid from escaping;
c. Consolidating and storing sperm and preventing emission
and premature ejaculation;
d. Consolidating the organs so as to prevent them
from descending.
A decrease in the above functions of Qi may cause various
kinds of hemorrhage, spontaneous perspiration, polyuria, salivation, spermatorrhea,
premature ejaculation, prolapse of the stomach, kidney and uterus.
The consolidating
and governing action and the promoting action of Qi oppose each other and yet
also complement each other. On the one hand, Qi has the function of promoting
the circulation of blood, and the transportation and distribution of body fluid.
On the other hand, it also has the function of controlling and adjusting the movement,
secretion and excretion of liquid substances in the body. The coordination and
balance of these two functions are essential for maintaining normal blood circulation
and water metabolism within the body.
5) Promoting Metabolism and Transformation
"Qi
hua" is a specific term in the science of TCM. It refers, in general, to
various kinds of changes taking place in the body under the action of Qi. Specifically,
it refers to the metabolism of fundamental substances, vital energy, blood and
body fluid, and the transformations which can occur between them. For example,
vital energy, blood and body fluid are formed in the following manner: ingested
food is changed into food essence, and food essence is, in turn, transformed into
vital energy, blood or body fluid, and these can then be changed into any one
of the others according to the physiological need of the body. The waste from
the eaten food and the products produced in the course of metabolism are changed,
separately, into feces, urine and sweat which are ready to be removed from the
body. All these are the specific manifestations of the action of the activity
of Qi. The dysfunction of Qi in performing its action will affect the whole metabolism
of the body. That is to say, it will affect the digestion, absorption, transformation
and transportation of food: the formation, movement and transformation of vital
energy, blood and body fluid; and the excretion of feces, urine and sweat; thus
causing various symptoms associated with abnormal metabolism. In short, the process
in which Qi performs its functions is the process in which the substances in the
body are metabolized, and in which the substances and energy are transformed.
Although
the above five functions of Qi are different, they enjoy close cooperation and
mutual support.
4. The Movement of Qi
The various functions of Qi are all
performed by its movement. TCM calls the movement of Qi as "functional activities
of Qi". Different types of Qi move in different ways. Theoretically, however,
we can put them in four basic ways: ascending, descending, exiting and entering.
Ascending refers to the movement from below; descending, from above; exiting,
from the interior; and entering from the exterior. These movements of Qi are vital
to life. Once they stop, life comes to an end. They are not only seen in promoting
and activating various kinds of physiological activities in the human body, but
also seen in motivating the physiological activities of the viscera and bowels,
channels and collaterals, tissues and other organs. For example, while the lung
performs its function, exhaling is exiting, inhaling is entering, dispersing is
ascending and keeping the inspired air flowing downward is descending. Of course,
this doesn't mean each organ functions in all four types of movement. Some organs
only function in a particular one. For instance, it is appropriate for the Qi
of the spleen to ascend and the Qi of the stomach to descend. However, in view
of all the physiological activities of the body, the four movements of Qi have
to be coordinated and balanced. Only in this way can the physiological functions
of the human body remain nor-~a1 In TCM, the physiological state in which the
four basic movements of Qi are coordinated and balanced is called "harmonious
functional activities of Qi". When they are uncoordinated and unbalanced
it is called "disharmonious functional activities of Qi". Because the
movements of Qi differ, the disharmonious functional activities of Qi are shown
in various ways. For example, over-ascending is known as "the abnormal rising
of Qi"; not descending on time, "the non-descending of Qi"; not
ascending on time or over-descending, "the sinking of Qi". Exiting too
much because it is unable to be contained is known as "the escape of Qi",
while an accumulation inside due to its being unable to exit is known as "the
accumulation of Qi" or "depressed Qi", and even "closed Qi"
when the accumulation is more severe. If Qi has difficulty in moving or its flow
is even partially obstructed it is called "the stagnation of Qi". As
to individual internal organs, the examples of the disharrn6-nious functional
activities of Qi are as follows: the non-descending of the Qi of the lung, the
sinking of the Qi of the spleen, the adverse rising of the Qi of the stomach,
the nonconsolidation of the Qi of the kidney, etc.
5. The Classification of
Qi
The Qi of the human body is classified into the following categories:
1)
Inborn Qi
Inborn Qi is also called "primordial Qi" or "genuine
Qi". It is the most important and fundamental of all.
(1) Formation
Inborn
Qi comes mainly from the innate essence stored in the kidney. But it also depends
on the supplement and nourishment of the acquired essence developed in the spleen
and stomach. This is what The Acupuncture Therapy And The Relation Between Healthy
Energy And Pathogen, a chapter of Miraculous Pivot, says: "The inborn Qi
is received from heaven and combined with food essence to nourish the body."
(2)
Movement
The inborn Qi commences from "the vital gate", the portion
between the two kidneys, passes the triple warmer and circulates throughout the
body. It goes inward to the five viscera and six bowels and outward to the muscles
and skin, i.e., the superficial layer of the body. It goes everywhere and acts
on all parts of the body.
(3) Functions
The inborn Qi has the functions
of both activating growth and development and promoting the functional activities
of
all the viscera and bowels, channels and collaterals, tissues and other
organs. Therefore, the inborn Qi is the motivating power of the vital activities
of the human body. Sufficient inborn Qi causes normal growth and development of
the body and heal-thy and vigorous activities of all the functions of the body.
Insufficient inborn Qi leads to late and slow growth and development, and reduces
all physiological functions. This is indicated by lassitude, general debility
and susceptibility to diseases.
2) Pectoral Qi
Pectoral Qi is the Qi stored
in the chest.
(1) Formation
Pectoral Qi is a combination of the fresh air
inhaled by the lung and the food essence derived by the spleen and stomach from
water and grain.
(2) Movement
Pectoral Qi is stored in the chest and poured
into the channels of the heart and lung just as Five Kinds of Flavor, a chapter
of Miraculous Pivot, says: "It goes out of the lung and circulates through
the larynx and pharynx. This is the reason why it exits when being exhaled and
enters when being inhaled." The book Classified Canon compiled by Zhang Jiebin
in 1624 A.D. says: "It goes down to the elixir field to be stored, and fills
the Point Qijie of the yangming Channel from which it continues to go downward
to the feet."
(3) Functions
Pectoral Qi, in the main, has two functions.
One is that it flows through the respiratory tract to promote the respiratory
movement of the lung and is involved in the loudness or softness of voice and
words. The other is that it fills the heart channel to promote and adjust its
beat, and to promote and adjust the circulation of blood and vital energy. It
also exerts an influence on the warmth and activities of the limbs. Therefore,
the manifestations of a deficiency of pectoral Qi are, often, the weakness of
the functions of the heart and lung, such as shallow breathing, soft voice, abnormal
heartbeat, slow blood flow, cold limbs, lassitude and moving with difficulties.
In clinical practice, it is often by the pulsation on the apex of heart that TCM
decides whether pectoral Qi is weak or not.
3) Nourishing Qi
Nourishing
Qi refers to the Qi circulating within the blood vessels and having a nourishing
function. As it flows through the vessels with blood, it has such a close relationship
with the latter that TCM often mentions them in a combined way "nourishing
blood". Compared with defending Qi, nourishing Qi belongs to yin, so it is
also called "nourishing yin".
(1) Formation
Nourishing Qi comes
mainly from the food essence transformed and transported by the spleen and stomach.
This is why a chapter on Arthralgia-Syndrome of Plain Questions says: "What
is nourishing 9i ? It is the essence of food and water."
(2) Movement
Nourishing
Qi originates from the middle warmer and enters the channels by way of the lung.
It circulates throughout the body along one after another of the fourteen channels.
(3)
Function
Nourishing Qi has two main functions. One is to produce blood, that
is, it flows into the channels through the lung and becomes a component of blood.
The other is to nourish the whole body. That is, it goes up and down along the
channels, circulatng round the body and thus providing nutrients for the physiological
activities of all the viscera and bowels, channels and collaterals, tissues and
other organs. So, a chapter on the Pathogens Attacking the Body of Plain Questions
says: "Nourishing Qi secretes its fluid, which enters the channels and turns
into blood, thus nourishing the limbs, the five viscera and the six bowe1s."
4)
Defending Qi
Defending Qi is the Qi moving outside the conduits and having
protective functions. Compared with nourishing Qi, it belongs to yang, so it is
also known as "defending yang".
(1) Formation
Defending Qi also
comes from the food essence transformed and transported by the spleen and stomach.
It is characterized by braveness in defence. That is why a chapter on Arthralgia-Syndrome
of Plain Questions says: "Defending Qi is a brave kind, which is produced
by food and water."
(2) Movement
Defending Qi circulates not within
but outside the channels. Being vaporized to the diaphragm and scattered in the
chest and abdomen, it travels between the skin and flesh. In spite of circulating
outside the channels, it still leans against the channels when moving.
(3)
Function
Defending Qi has three functions. The first is guarding the surface
of the body against exopathogen. The second is keeping a relatively constant body
temperature by controlling the opening and closing of the pores and adjusting
the excretion of sweat. The third is nourishing the viscera, bowels, muscles,
skin and hair.
In addition, the circulation of defending Qi is associated with
sleep. Man goes to sleep when defending Qi circulates in the interior of the body,
whereas he wakes up when it circulates on the surface of the body.
When defending
Qi is insufficient, the defending function of the human body is weakened, the
exopathogen invades the body easily, and the disease is hard to cure. Abnormal
circulation of defending Qi may cause sleep disorders. The longer defending Qi
circulates on the surface of the hod y, the shorter the duration of sleep, while
the longer it circulates in the interior of the body, the longer the duration
of sleep.
Nourishing Qi and defending Qi have the same source. The former
circulates within the channels, has the nourishing function and belongs to yin,
whereas the latter circulates outside the channels, has the function of guarding
the exterior of the body and belongs to yang. Only when they coordinate with each
other can the opening and closing of the pores be kept normal, the body temperature
constant, and the defending ability strong. When they can not coordinate with
each other because of an attack by exopathogen, such symptoms as aversion to wind,
fever and sweating will occur.
Extracted from "Basic Theory of Traditional
Chinese Medicine"