There are many characters used for the vital function of free-flow of blood and qi throughout the body, but the most important and commonly used is tong (通).
The character tong (通) describes any kind of communication which is free from obstruction; it is particularly used for the spreading and free movement of qi, but can describe communication between people as much as free-flow within the organism. In classical Chinese it is to open the way, to open dialogue, to allow the mingling of different things, ideas, people. It is to give free access to something; to penetrate and to permeate. Read more