This is one of the most commonly asked questions about Chinese medicine and,
as you'll see, is rather difficult to answer. The Chinese concept of Qi
(pronounced "chee" and sometimes written chi) is not easily translated into
English. Variously described as "energy" and "life force," it is believed to be the
most basic substance of the universe, that of which all things are composed.
Although it is everywhere fundamentally the same, it's capable of changing both
in form and in function, wearing a "different hat" in different places and
assuming different roles. As such, Qi is perhaps better described by what it
does rather than what it is.
The promoting, activating function of
Qi is seen in the growth and development of our bodies, the activities of our internal
organs, and the circulation of our Blood and Body Fluids. If Qi is weak and the promoting
function impaired, our growth will be slowed, our organ-function weakened, and our
circulation impaired. Thus we can see a malnourished child (one who has taken in
less postnatal Qi, in the form of nutritious food) will grow to be sickly and weak,
while a well-nourished child will grow quickly and with strength.
Warming is the function of
Yang Qi, and in particular of the Spleen
and Kidney Yang. Without Yang Qi, the source of which is the Kidneys, the Spleen
would lose its ability to transform our meals into Food Qi (Gu Qi) and we would
become malnourished. People who tend to be cold and suffer from poor digestion
(loose stools, abdominal bloating, cramping) may be diagnosed with a deficiency
of Yang Qi.
Defensive Qi (Wei Qi) guards us from the
external pathogenic influences known as Evil Qi (Xie Qi), such as the common cold
virus, by consolidating the surface of our skin and regulating the opening and closing
of the pores. In addition, it warms, moistens, and partially nourishes the skin and
muscles and regulates the body temperature.
Prolapse, or sinking, of the internal
organs is preventing by the lifting power of Spleen Qi. If the Spleen Qi is
weak, it may lead to prolapse of the uterus, stomach, or anus. Hemorrhoids
is an example of Qi sinking combined (usually) with Heat and stagnation.
The Qi of the Spleen is also the force
that keeps Blood from extravasating (spilling from the arteries and veins),
while the Qi of the Kidney and Urinary Bladder prevents urinary incontinence,
wetting the bed, or waking up multiple times to urinate.
Spleen Qi transforms the food we
eat into Food Qi (Gu Qi), some of which is then transformed into Blood by Heart
Qi; Kidney Qi transforms fluids into useable Body Fluid and excretable urine.
The Lungs transform the air we breathe into Pectoral Qi (Zong Qi) with the help
of the Spleen and Kidneys.
Spleen Qi transports Food Qi upward
to Heart, where it becomes Blood; Heart Qi transports Blood to the rest of the body;
Lung Qi transports moisture to the surface of the body and its own Qi down to the
lower portions of the body. Liver Qi transports Qi in all directions.
That's an interesting question and can make for a heated debate, one that
constitutes the main argument of those who feel they can deny the validity
of Chinese medicine. Scientists can measure a difference in electrical
conductivity on the surface of the skin at acupoints, but they cannot yet
account for the pathways of the meridians nor, with any certainty, for the
effects of acupuncture or moxibustion on areas distant to the points stimulated.
(For instance, moxa on the point UB-67, Zhiyin, located beside the fifth
toenail, is often used successfully to correct a malposition of the fetus, breach
presentation, prior to childbirth.) Whether or not Qi exists as it was explained
by the ancients—an uncertainty that leads TCM researchers and philosophers
to use the term "TCM theory," rather than "the Laws of TCM"—the venerable,
somewhat mystical-sounding-to-Western-ears explanations of the earliest Chinese
philosophers still serve to guide practitioners of this medicine in directions that
prove clinically useful. Until a better theory is introduced or (more likely, I believe)
the current theories are scientifically validated, the ancient theories of Qi,
its movements, and its meridians will continue to guide us in (and the martial artists,
and meditators, and massage therapists) our practices.
The argument is far from resolved and will likely remain so for some time, perhaps eternally.
For two interesting perspectives on the debate, both from acupuncturists, have a look at
Opposing Viewpoints on Qi.