What Is Qi in Chinese medical classics

TCM starts with the concept of Qi (pronounced "chee").
1. Qi is energy in the very broadest sense possible.
2. Qi is universal.
3. Qi embraces all manifestations of energy, from the most material aspects of energy (such as the earth beneath your feet, your computer, and flesh and blood) to the most immaterial aspects (light, movement, heat, nerve impulses, thought, and emotion).

Life, it is said in the Chinese medical classics, is a gathering of Qi. A healthy (and happy) human being is a dynamic but harmonious mixture of all the aspects of Qi that make up who we are.

Qi is in a state of continuous flux, transforming endlessly from one aspect of Qi into another. It is neither created nor is it ever destroyed; it simply changes in its manifestation.

In order to talk about the relationships between the various aspects and manifestations of Qi within a given context, Chinese philosophy employs the concept of yin and yang.