Yin and Yang were first discovered and summarized by the ancients in the process of observing natural phenomena. We all have an experience: the sun can shine on the south of the mountain, but it can't shine on the north. This phenomenon was also discovered by the ancients. They call the sunny side in the south and the sunny side in the north yin.
Later, the concept of Yin and Yang gradually extended to other aspects, taking Yin and Yang as the principle to explain everything. As long as it is extroverted, upward, warm, bright and energetic, it belongs to Yang; As long as it is introverted, healthy, cold, dark and relatively static, it belongs to Yin.
People with positive physique are often restless and restless, because the yang is full of heat. For people with negative constitution, we can also sum up four main characteristics: cold, wet, quiet and hiding.