Changshan belongs to the traditional Chinese medicine of gushing and vomiting, with the efficacy of gushing and vomiting phlegm and saliva, intercepting malaria, mainly used in the treatment of phlegm and drink (pathological products formed by the impaired metabolism of water and liquid) stagnation, chest and diaphragm plagued, malaria and other diseases. Changshan is the dried root of Changshan, a plant of the family of Thuja. It is bitter, pungent, cold and poisonous in nature, and belongs to the lung, liver and heart meridians, and has the efficacy of gushing and spitting out phlegm and saliva, and stopping malaria. Clinically, it can be used for the treatment of phlegm and drink accumulation, chest and diaphragm congestion, malaria and other diseases. It should be noted that the drug has emetic side effects, so the dosage should not be too large, in addition to pregnant women should be used with caution. If you need to use the drug, it is recommended to go to the hospital, under the guidance of a professional physician to identify the evidence, do not self-medication, so as not to cause adverse effects.