Yin and yang balance is as clear as night and day.
When I was younger (about seven years old) I had a little yin and yang pendant. I bought it myself. I didn't have much of an idea of what the symbol meant at the time.I just liked it.It felt very calming.
Later on, I would come to realize its significance.
As I found out, TCM philosophies come from the doctrine of Taoism. Many thoughts in Taoism are based on watching the natural world as well as the way in which it works.
TCM draws broadly on natural metaphors. The symbolic visions of the body are founded on observing nature. This can be fully seen in Yin-Yang and Five Element theory.
The Yin and yang concept is the base of many branches of Chinese philosophy and science. In addition, it is the principle guideline for TCM. Yin-yang is an essential principal of different groups of exercise and Chinese martial arts like qigong and baguazhang, taijiquan.
Yin-yang is not an actual substance or force the way it might be envisaged of in western, Yin-yang is a collective way of describing interrelations and interactions of the natural powers that happen in the world.
These forms of relationships become important when they come into contact with the body's physiology and anatomy.
If your body's yang is frail it will not be able to ward off viruses. If your yin is weak then there is not enough support and for your yang then the result is the same. It also applies to social constructions for example rich and poor.
Characteristics of yin
Characteristics of yang
Yin-yang are conflicting yet mutually dependent they are not able to survive on their own. Without cold there is no hot. without movement there is no stillness. Without darkness there is no light.
This is a short two minute video explaining further about yin-yang and how it relates to TCM.