The Yellow Emperor asked, "Why does the Lesser Yin govern the kidney and why does the kidney govern water?" The kidney is the most bright and the most Yin, holding water. The lung is the sun, and the Shaoming meridian is the winter meridian. Therefore, its root is in the kidney and its terminal is in the lung, both of which are due to water accumulation. Emperor's Day: How can the kidneys accumulate water and fall ill? Read Bo said: The kidney is the gateway to the stomach. When the door is closed, it is not in good condition, so water and heat accumulate. It must be a mistake of the character "bone". ② Ankle: Originally absent, weighing the sail of the "Tai Su".