The root causes of fire include dietary factors, mental factors, exogenous evil and other factors such as prolonged illness and overwork. 1. Dietary factors: usually like to eat greasy, spicy and stimulating food people, easy to lead to stomach heat produced too much, heat spread to the body organs, fire symptoms. 2. Mental factors: due to a long period of depression or irritability and other bad mood interference, resulting in excessive liver fire, fire symptoms. 3. Exogenous evil: the body is exposed to wind-cold, wind-heat or summer-heat, etc., due to untimely or incorrect treatment, resulting in the presence of evil in the body, which induces the symptoms of fire. 4. Other factors: excessive sexual intercourse or prolonged illness, resulting in Yin fluid injury, deficiency of essence and blood, or Yin deficiency and hyperactivity (Yin fluid deficiency leading to exuberance of Yang Qi), etc. will appear on the fire symptoms. It is recommended to reduce the fire in a timely manner to regulate or treat the symptoms as soon as possible.