To treat disease in Chinese Medicine we must seek its root in yin and yang.
One of the most important chapters in the Huang Di Nei Jing Su Wen is chapter 74. It describes exactly how a disease will manifest.
Huang Di, The six qi are not identical in their conforming to tip or root, how is that?
Qi Bo, Among the qi are those conforming to the root; there are those conforming to the tip and root; and those conforming to neither the tip nor the root.
Fang Yaozhong, To conform refers to the focus in diagnosing and treating the disease.
Qi Bo, The shao yang and the tai yin conform to the root.
Wang Bing, The root of shao yang is fire; the root of tai yin is dampness.
Zhang Jiebin, Of the six qi shao yang qi is the minister fire. That is shao yang qi is the transformation product of fire.
In other words, the root of shao yang is fire and the root of tai yin is dampness.
When looking for a shao yang disease look for, bitter taste, dry throat and dizzy vision.
When looking for a tai yin disease look for, abdominal fullness and vomiting, inability to eat, severe spontaneous diarrhea, abdominal pain.
The shao yin and the tai yang conform to the root and the tip.
Wang Bing, The root of shao yin is heat; its tip is yin. The root of tai yang is cold, its tip is yang.
The tip of shao yin is yin because it is one of the three yin. The tip of tai yang is yang because it is one of the three yang.
Shao yin disease can manifest as heat or yin. In shao yin disease look for a deep thin pulse and a desire to sleep.
Tai yang disease can manifest as cold or yang. In tai yang disease look for a floating pulse, painful head and nape, and an aversion to cold.
The yang ming and the jue yin conform to neither the tip or the root, but conform from the center.
The center of yang ming dryness is tai yin dampness. In yang ming disease look for signs of excess stool and heat. When the tai yin dampness fails to nourish the yang it becomes excessively dry and hot.
The center of jue yin wind is shao yang fire. In jue yin disease look for signs of dispersion thirst, qi surging upwards striking the heart, painful heat in the heart, hunger without desire to eat. When the shao yang fire is weak a separation of yin and yang occurs.
These are the ways a disease can manifest and how to recognize it.