The Yellow Emperor said: "All intermittent fevers are caused by
wind, and they have (specific) periods of dormancy and outbreak. Why
is this so?"
Chi'i Po replied: "At the beginning of the development of a yao-illness,
the (patient's) fine hair rises; he will stretch out (his four limbs)
and yawn. Then an outbreak occurs. (The patient suffers from a feeling
of) cold that causes him to tremble and his jaws to chatter. His waist
and his back ache both alike. As soon as these chills diminish (the
patient) feels heat in both the internal and external (regions of his
body). His head aches as if it were about to burst; he is thirsty and
yearns for something cold to drink."
The Yellow Emperor asked: "Which influences cause these (symptoms)?
I should like to hear about the (underlying) principle."
Ch'i Po said: "(The underlying principle of this illness may
be seen in) the mutual contest of yin and yang (influences),
as they cause each other depletions and repletions, and as they move
into each other’s (territory). When yang (influences) enter the yin
(conduits), a repletion emerges in the yin (conduits), while
a depletion occurs in the yang (conduits). If a depletion strikes
the yang-brilliance (conduit, the patient will suffer from) cold
that causes him to tremble, and his jaws to chatter. If the great-yang
(conduit) is depleted, pain is felt in the waist, the back, the head,
and the neck. If all three yang (conduits) are affected simultaneously
by a depletion (of influences), the yin influences will be in excess.
If the yin influences are in excess, cold develops in the bones, accompanied
by pain. Cold is generated inside (the body) with the result that both
(the body’s) center and its external (areas) all suffer from cold. In
case of an excess of yang (influences), external heat develops; in case
of a depletion of yin (influences), external heat develops; in case
of depletion of yin (influences), internal heat develops. If
(the body) suffers from heat both internally and externally, panting
and thirst result, and (the patient) yearns for cold drinks. All such
(illnesses) are caught in summer as harm caused by heat. An abundance
of heat influences is stored inside the skin and outside of the intestines
and the stomach. This is the area where the (body's) constructive influences
reside. As a result of this (condition), the openings through which
perspiration leaves relax (their tight closure), and the pores open,
and one is affected by the influences of autumn, in that sweat leaves
(the body) and meets with wind, or one gets (the illness) while bathing.
Water influences settle inside the skin, and reside together with one's
protective influences. The protective influences, however, move through
the yang (conduits) during the day-time and through the yin
(conduits) during night. Here now, the (evil) influences will be able
to (follow the protective influences into) the yang (conduits)
and move outwards to the external (areas of the body), and they will
be able to get access to the yin (conduits) and extend into the
internal (areas of the body). Because the (evil influences) reach into
the internal and into the external (areas of the body), daily outbreaks
(of the illness) occur."
The Yellow Emperor said: "What is the reason when the outbreaks
occur only every other day?"
Ch'i Po said: “The (evil) influences reside deep (in the body); internally
they reach into the yin (areas of the body). Only the yang
influences emerge; the yin (influences) and the evil (influences)
remain in the interior. The contest between yin and yang
(influences) does not permit (the evil influences) to emerge (at all
times). Thus (the illness) breaks out only every other day."