What is Qi?
The theory of qi comes from an ancient Chinese naturalist philosophy called Daoism. The word qi is very difficult to translate since we have no similar word or concept in the western world. Qi has been translated as energy, ether, vital force, life force, material force, or moving power. These definitions are partly correct; but since there is no similar concept in our culture, it is important not to fall into the habit of using a narrow definition for qi. The definition of qi actually changes according to different situations.
Daoist philosophy postulates that the substructure of the entire universe is qi.This substructure, while providing the impetus for change/transformation, simultaneously is responsible for maintaining continuous transformations throughout the universe.In the ancient text Yi Ching (Classic of Changes) Daoist philosophy postulates that the only constant in this universe is change.
When qi condenses, matter is formed and when qi is more disperse, space is formed.So according to this theory, qi is simultaneously energy and matter. When qi is dense it is called yin and when qi is light it is call yang.
Qi of the body
Qi is a real substance that can be felt and worked. When we talk about the qi of the body, we are referring to the non-material part of the body. In this sense we're talking about energy, however, it is preferable to refer to this as qi.
Qi is the finer, less dense portion of the body. The ancient text Nei Ching (The Inner Classic) defines the qi of the body as a type of matter; less dense than the flesh, but denser than the substructure of the universe which is called da (great) qi. Qi is that part of the body that is non-material but on the verge of becoming matter.
Qi is one of the components of the body along with organs, tissues, bones and fluid.Qi has many functions, but its primary function is initiating and maintaining transformations. For example, this includes the transformation of food to flesh and blood, the absorption of oxygen and the elimination of carbon dioxide, and the maintenance of even body temperature.Even appropriate emotional responses, including decision making, are the result of qi.Qi also maintains the relationship between your body and the environment.
Qi is present in all body cells and also flows in larger concentrations within specific pathways called channels or meridians. The largest storehouse of qi in the body is in the area called the lower dan tien (field of elixir). This is the entire lower abdominal cavity, between the navel and the top of the pubic bone, which the ancient text Nan Ching (The Classic of Difficulties) refers to as the space between the kidneys.