Qi and blood are the motive force and source of human life, and qi is yang. Blood is yin, which can be used for both qi and blood. It nourishes viscera and limbs, and qi plays a role in warming the heart, strengthening the body and promoting. Qi deficiency will make you afraid of cold, lack of qi will make you lazy to talk, limbs are not warm, and the defense of qi is unstable, which will lead to colds, poor body resistance, and qi stagnation will lead to blood stasis, which will lead to poor blood circulation and impassability of meridians. Pale face, no need to wait for limbs, deficiency of both qi and blood will lead to a series of sub-health States, seriously damaging the function of the five internal organs, and all diseases will arise from this. However, body fluid and essence and blood are important fluids in the body, which are yin in nature and are caused by the transformation of qi, so body fluid will be insufficient, which will also cause symptoms of yin deficiency and yang hyperactivity and excessive heat in the body. For example, people with yin deficiency in diet should eat more shellfish.