The opposition of yin and yang:

Their ability to struggle with and thus control each other in order to maintain a relative physiological balance
through mutual opposition of yin and yang. “When yin predominates, yang will be diseased; when yang
predominates, yin will be diseased.

The interdependence of yin and yang:

Neither can exist without the other, they are the condition for each other’s existence. ‘Yin remains inside to
act as a guard for yang, and yang stays outside to act as a servant for yin.”

The inter-consuming-supporting relationship of yin and yang:

The two aspects of yin & yang within any phenomenon are not fixed, but in a state of continued mutual
consumption and support. Various functional activities (yang) will necessarily consume a certain amount of
nutrient substance (yin) to result in consumption of yin leading to a gain of yang. Nutrient substances will
also consume a certain amount of energy, consumption of yang, leading to a gain of yin.

The inter-transforming relationship of yin and yang:

Extreme yin will necessarily produce yang and extreme yang will produce yin; i.e. severe heat will give birth
to cold, and severe cold will give birth to heat.