Every phenomenon in the universe can be divided into yin and yang. So yin is the moon and yang the sun. Yin is cold, yang is hot. Yin is female, yang is male. Yin is water, yang is fire. These concepts can certainly be traced back to the Shang dynasty from 1600 BC – 1100 BC.
However, you can also know more about old chinese medicine online.
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In addition, there is the five elements theory which maintains that everything in the universe can be broken down into wood, fire, earth, water, and metal.
According to TCM there are twelve (or some say fourteen) meridians, or channels, in the body through which run qi, which is simply energy.
When the qi is flowing freely through these meridians which run from the skin to all the major organs, yin and yang are in balance and the body is healthy. It is when yin and yang become out of balance that the qi is unable to flow as it should to the various organs and ill health is the result.
Acupuncture is one of the most common ways to treat the problem. Acupuncture uses very fine needles which are inserted into the skin to a depth of perhaps ½ an inch into what are known as acupuncture points along the meridians.
Again, depending who you believe, there can be 365 of these acupuncture points or as many as 2,000. Today, acupuncture needles are made of stainless-steel and are for one-time use.