Our human body is particularly complicated. When our meridians are different, our bodies will send out many uncomfortable signals to ask for help. This is what is often said in Huangdi Neijing: "The pain is impassable, and the general principle is painless."

"Tong" in Chinese medicine originally refers to the smoothness of qi and blood. The channel through which qi and blood run is called meridians, so "communication" means that meridians are unobstructed, and meridians include meridians. Meridian is connected with the internal organs and external limbs of our body, criss-crossing, covering every part of our body, connecting the internal and external organs and limbs of our body into an organic whole, which constitutes the regulation system of our human body function.

The importance of meridians has been mentioned many times in Huangdi Neijing, which may decide our life and death, regulate excess and deficiency, run qi and blood, nourish yin and yang, and smooth joints. This passage, which is used to connect zang-fu organs with body surface and whole body tissues, must not be blocked, but must be kept unobstructed. Once blocked, it will cause disease, and the phenomenon of qi stagnation and blood deficiency will occur, so that our internal organs will not be nourished, and the disease will take advantage of it.

All diseases are caused by qi and blood stasis. Qi and blood complement each other, qi stagnation and blood stasis. Qi and blood can cause various pains, such as swelling, tingling and soreness. Therefore, it can be seen that "inability" is the root of pain and even all diseases. The basic principle of traditional Chinese medicine in treating pain and other diseases is the word "tong", which is to make the meridians unobstructed and the qi and blood run smoothly. Only when the meridians and qi and blood are smooth can our internal organs be nourished, so as to resist external evils and achieve a balance between yin and yang, and our bodies will be healthy.