Yin is one half of both the Tai Chi and Yin-Yang theory. The feminine and negative principle (as in passivity, darkness, cold, wetness) in nature that according to traditional Chinese cosmology combines with its opposite Yang to produce all that comes to be.

There are different phases of interaction between Yin and Yang:

  • Opposition
  • Interdependence
  • Mutual Consumption
  • Inter-transformation

In the context of medicine, Yin corresponds to:

  • Front
  • Body – Inferior (area below the waist)
  • Interior (organs)
  • Yin organs and organ structure
  • Blood & body fluids
  • Ying-Qi (Nutritive Qi)