The phenomenon of fever receding and coming back means that the cause of fever still exists, but the body still has a certain thermoregulatory effect, so the phenomenon of fever receding and coming back. You need to find out the cause of the fever and treat it. Go to the hospital and check the blood test and C-reactive protein to see if the fever is caused by an infection, as long as the C-reactive protein is elevated, the fever is usually caused by an infection. If accompanied by elevated white blood cells in the blood routine, it means that it is a bacterial infection, and need to use antibiotics for treatment, it is recommended to take oral cephalosporin antibiotics or penicillin antibiotics, such as cefixime or amoxicillin. If an allergy to either of these drugs is present, they should not be used and azithromycin is recommended for treatment. If simple C-reactive protein is elevated, the fever is usually caused by viral infections, and antiviral drugs, such as Pu Di Lan Anti-inflammatory Oral Liquid or Blue Scutellaria Oral Liquid, are needed, which have better antiviral effects.