The concept of Yin and Yang has been practiced for over centuries: Yin is recognized as the shady side of the hill, assuming darkness, while Yang is the sun over the horizon; establishing brightness.

The theory started from the Chinese peasant perspective from day to night; as a cyclical movement with two stages, one changing to another. It could also be defined as the change in different stages at once.

Everything in the world has an opposition, and its usage is relative to something else. Yin and Yang 

Yin and Yang

are interdependent, in other words, they need each other to exist and nothing can be in its entirety one or the other. The seed to start one is within the other, there is always a peak or a change that marks the change in stage. For instance, the day starts changing to night when it reaches midday. 

This transformation is started because of two conditions:

  • Internal and external factors
    • For example a caterpillar could turn into a butterfly (Internal) because of their disintegrated tissues(external factors), but not just anything could turn into a butterfly because they lack the ability to do so.
  • Time 
    • There is a certain stage a caterpillar must turn into a butterfly.

They create a balance and when they lose that balance, they change proportions to achieve stability.

  • Prevalence of Yin and Yang
    • A decrease one produces an excess of the other 
  • Weakness of Yin and Yang
    • A weakness in one, creates an excess in the other

The Yin and Yang concept also applies to the duality of states in condensation and parallel the duality of Heaven and Earth. The less dense form of matter is Yang, being that it compares to pure energy in activity, and expansion that rises, while coarser forms represent the Yin adding to the condensation and materialization.

Chinese medicine could be traced to the structural components of Yin and Yang.

Treatment strategies include:

In the Body Structure, the nature of Yang is to be on the outside and protect, while the nature of Yin is to flourish the body.

Yang

  • Superior
  • Exterior – it protects the body from the outside
  • Head – energy flows to the top and has the most heat correlation
  • Posterior – Lateral surface of limbs
  • Back – channels fight the pathogenic factors from outside of the body
  • Function of organs–  secrete impure substances and are in constant activity as to achieve Qi
  • Above waist- mainly targeted by infective agents like wind
  • Qi- warming protecting and defending
  • Defensive Qi- circulates the skin and muscle

Yin

  • inferior
  • Interior – maintains organs to nourish the entirety of the system
  • Body – cold form of the body
  • Anterior -medial surface
  • Front – contains channels that allows the body to carry energy and ailments produced outward
  • Structure of organs- they store vital substances which are Qi; Blood Bodily Fluids and Essence.
  • Below waist- mainly targeted by infective agents like dampness
  • Blood and Bodily fluids- blood is denser than is Qi and nourishes the vital activities of the body
  • Nutritive Qi- circulates the internal organs