Sudden fever is mainly a symptom of upper respiratory tract infection caused by viral or bacterial invasion due to low immunity of the body. You can check the blood routine, blood sedimentation and chest X-ray, through the blood analysis, if the fever is caused by viral, you can use antiviral drugs symptomatic treatment, such as ribavirin. If the fever is caused by bacterial infection, it can be treated with antibiotic drugs, such as penicillin, cephalosporin, macrolides and quinolones. Oral Chinese medicines can also be taken, such as Pu Di Lan Anti-inflammatory Oral Liquid, Blue Scutellaria Oral Liquid, Qing Kai Ling Granules, Ban Lan Gen Granules, Antelope’s Horn Granules, Lian Hua Qing Dao Granules and other medicines for clearing heat and removing toxins. If the fever is caused by wind-cold flu, it can be treated with the addition and subtraction of Jingpang Defeating Toxin Powder, which has the effect of relieving the epidermis with pungent and warmth. If the fever is caused by wind-heat cold, Yin Qiao San can be added and reduced, which has the effect of pungent and cool to remove the surface. Combination of Chinese and Western medicine can shorten the cycle and improve the efficiency of fever treatment.