If Xiaoqinglong Tang is taken as prescribed by the doctor, side effects usually do not occur. However, since this formula contains many warm and dry products, it should not be used by people with dry cough without phlegm or phlegm-heat evidence of yin deficiency. Xiao Qing Long Tang is composed of Ephedra, Paeoniae Alba and Sinensis. It has the efficacy of relieving exterior cold and dispersing cold (removing cold from the muscle surface), warming the lungs and resolving fluid (promoting the flow of stagnant fluid by warming the lungs). Clinically, it is mainly used for the treatment of external cold and internal drink syndrome, with symptoms such as malignant cold (fear of cold) and fever, head and body pain, no sweating, wheezing and coughing, sputum and saliva being clear and thin but large in quantity, chest congestion (meaning that the qi in the chest is blocked and impassable), or dry vomiting, or phlegm-drinking (the pathological product formed by the metabolism of water-liquid disorders) wheezing and coughing, and not being able to lie down, or body pain and heaviness. In addition, if the external cold evidence is mild, Gui Zhi can be removed, and Ephedra can be replaced by sizzling Ephedra; if there is both heat and irritability, add gypsum and Scutellaria to clear the heat; if there is also phlegm in the throat, add almonds, Sagittaria, and Fenghuangdonghua to dissolve phlegm, lower the qi and calm the wheezing; if there is nasal congestion and a lot of nasal mucus, add xin yi and Cang Er Zi to clear the nasal orifices; and if there is also oedema, add Poria, Poria to facilitate the water retention and eliminate oedema. The specific application of drugs should be under the guidance of Chinese medicine practitioners, not blindly use their own medicine.