If the four seasons always get angry, we should consider yin deficiency and fire flourishing, and use traditional Chinese medicine to nourish yin and reduce fire. The hyperactivity of fire due to yin deficiency also belongs to the sub-health state and the category of decreased immunity. Nourishing yin and reducing fire in TCM is to improve human immunity. People with hot constitution eat white Dihuang pills, while people with cold constitution eat Liuwei Dihuang pills.