then starts decreasing as it flows towards the feet. At the feet, Qi changes polarity, i.e. it flows
from the Yang Stomach channel to the Yin Spleen channel, but its potential is still decreasing as
it flows towards the chest area. When it reaches the chest the potential is minimum (the water
has reached the bottom of the hill again). The Qi from the Spleen channel then connects
internally with the Heart channel and a new 4-channel cycle starts in exactly the same way. The
cycle of Qi in the first four channels can be seen in Figure 1.2(57). Figure 1.3(58) shows the
circulation of Qi in the 12 channels.
The implication of all this is that the head is the area of maximum potential of Qi and therefore
intrinsically prone to rising of energy (or pathogenic factors) to the top, for example, the rising of
Liver-Yang, Liver-Fire, Liver-Wind, or Heart-Fire. Conversely, clear Yang Qi failing to rise to
the top may lead to the obstruction of the head by Phlegm or Dampness.
The head is also the area of concentration of Yang energy as all the Yang channels directly meet
and join up in the head. In fact, as far the superficial pathways are concerned, only Yang
channels reach the head. For this reason the head is variously called "the confluence of Yang" or
"the Palace of Yang" or "the Palace of clear Yang"4(59).
However, Yin Qi obviously also reaches the head but only internally. Of the Yin channels only
the Heart and Liver reach the head internally (deep pathway). All the other Yin channels reach
the head indirectly via their divergent channels as each Yin divergent channel merges with its
related Yang divergent channel at the neck area (Figure 1.4(60)). Thus both the clear Yang from
the Yang organs and the pure essences from the Yin organs reach the head.
As far as headaches are concerned, the two Yang channels which are most frequently involved
are the Gall-Bladder and Bladder. Of the Yin channels, the two most frequently involved are
Liver and Kidneys.
Diagnosis
Headaches can be diagnosed from two perspectives: from the point of view of channels or
internal organs. Both of these are equally relevant in clinical practice particularly from the
acupuncturist's perspective. I will discuss the main diagnostic pointers from three viewpoints:
- Diagnosis according to channels
- Diagnosis according to type of pain
- Diagnosis according to amelioration and aggravation.
The diagnosis according to the internal organs will be discussed under the next heading,
"Identification of patterns".