By reviewing the relevant passages on "the clear and the turbid" (qing zhuo) in
the Inner Canon of Yellow Emperor
(《黄帝内经》), and analyzing their relationship through the theory of
yin
-
yang
opposition and unity, this study found that the clear and the turbid form a pair of opposing but unified concepts is similar to
yin
and
yang
. The ascending and descending movements of clear and turbid
qi
are closely related to the body's
qi
movement. Among the five
zang
organs, due to their different physiological characteristics, distinctions exist such as "the foot-
taiyin
channel exclusively receiving the turbid", "the hand-
taiyang
channel exclusively receiving the turbid of
yang
," and "the hand-
taiyin
channel exclusively receiving the clear of
yin
". Furthermore, seasonal climatic changes correspond to the ascending and descending movements of the clear and the turbid, which help the body adapt to seasonal variations. This principle of mutual correspondence between the macrocosmic
yin
-
yang
of nature and the microcosmic clear-turbid of human body can be applied in acupuncture clinical practice. By analyzing and understanding the theory of clear-turbid ascending-descending, this study can provide insights for syndrome differentiation and treatment in future practice.