The ancients summed up the causes of human diseases as six factors, namely wind, cold, summer heat, dampness, dryness and fire. That is, the six states of nature. These six states are not pathogenic in normal circumstances. It hurts only when it's too bad or too bad. For the body, the cause of disease is internal, external and non internal and external causes. The unity of heaven and man in the Yellow Emperor's Canon of internal medicine is a description of the nature and the human body. Six or seven of nature can cause disease, and natural animals and plants can also cure diseases. Every kind of animal and plant in nature has its own personality.
The character is relatively peaceful, can be used for a long time, that is, food, vegetables and so on. Therefore, the book of Materia Medica records that the grain of the grain is peaceful and can be taken for a long time. So, in nature, the nature of the gas bias is relatively large, it can be used as a drug. This part of plants and animals are cold, hot, warm and cool respectively. For example, hot drugs, can drive the body's cold; cool drugs, can nourish the body Yin blood, clearing heat storage, etc.. Using the bias of nature plants to reverse the deviation of human body, so as to achieve the effect of treatment.