Yin and Yang is another one of the most important concepts necessary to understand Chinese medicine. Yin and Yang appear everywhere in life. Male is yang and female is Yin; sun is Yang and moon is Yin; fire is Yang and water is Yin; bright is Yang and dark is Yin; up is Yang and down is Yin; good is Yang and bad is Yin; Happy is Yang and sad is Yin. In your life span when you are young, you belong to Yang, and, when you become older, you belong to yin. This goes on and on.
Overall, Yin and Yang describe nature opposites or contrary aspects and how those opposites or contrary aspects are actually complementary, interconnected, and interdependent in your body, your emotional state of mind, the natural world, and the universe. How they give rise to each other as they interrelate to one another is why everything has both Yin and Yang aspects. Yin and Yang must be balanced with a portion of the opposite element in each section; otherwise the order of the system will be broken. Yin and Yang is an indivisible whole. You cannot separate Yin and Yang. According to Chinese medicine, if Yin and Yang become separated, then life will be end because neither Yang nor Yin itself can bear life.
Acupuncture can regulate Yin and Yang and restore the balance in your sick body to regain your health. That is why my logo uses a needle that penetrates the Yin and Yang symbol.