Dexamethasone has anti-shock, anti-inflammatory and anti-allergic effects, if applied in first aid: i. Anti-shock effect, can be applied to various causes of shock, low blood pressure and other symptoms. Second, anti-inflammatory effect, can be applied to pneumonia caused by extensive pulmonary edema, or laryngeal edema caused by local airway obstruction, after the application of dexamethasone can well control its inflammation, reduce its edema, so as to alleviate the symptoms. In addition, it can also be applied to acute nerve pain caused by nerve compression due to lumbar disc herniation, and the application of dexamethasone can eliminate local nerve edema, thus relieving the symptoms. Third, anti-allergic effect, some acute symptoms of allergy, such as generalized urticaria, laryngeal edema, after the application of dexamethasone can relieve its symptoms, and also after being bitten by insects or animals, the application of dexamethasone can also local anti-allergic treatment.