The Spleen manufactures Qi from the transformed essence of food and drink. In the Heart, this mixes with the extracted Qi of air and is transformed into Blood through a process known as red transformation.
One of the five functions of Qi is holding (Qi transforms, transports, warms, protects, and holds). This capacity of holding gives it a tension. That is, there is potential energy in Qi. The potential energy of Qi is Blood, which is the realized potential of Qi. Blood possesses the lack of tension which results from Qi transformation (just as a spring relaxes once it is released), and imparts this quality into us. Blood gives the sensation of comfort and relaxation, and of smooth unimpeded movement. It is the physical substrate which imparts the Liver’s function of free flow (see Benevolence – The Virtue of the Liver). Blood is the foundation for a fluid sense of self arising from rootedness and self-esteem, both in turn imparted by Blood. Qi is dynamic and creates movement, Blood is receptive and moves of its own accord. Modern cardiology understands that the heart does not pump the Blood, but instead acts as an accelerator for a circulatory system whose movement is self-generating. Qi creates hunger, Blood creates fullness. The relationship between Spleen Qi and Heart Blood is reflected in the Chinese herbal formula Gui Pi Tang, or Restore Spleen Soup.
