It is important to find out the cause of fever of unknown origin in children, which usually requires a specific examination at the hospital to clarify. First of all, it is recommended to check the chest X-ray to exclude fever caused by respiratory system infection, and also to check the blood routine to observe whether there is an increase or decrease in white blood cells, and to do a C-reactive protein test to see if the fever is caused by inflammation. If the fever is caused by inflammation, C-reactive protein is usually elevated, and mycoplasma antibodies are also checked, so it is likely that the fever is caused by Mycoplasma pneumoniae infection, and appropriate medication is often needed to treat the cause according to the test results. In addition, fever symptoms also require antipyretic treatment, especially if the body temperature is greater than 38.5 ℃, it is recommended to take oral ibuprofen suspension, that is, Merlin for antipyretic treatment. If the body temperature is lower, below 38.5℃, it is recommended to take oral Chinese medicine to reduce fever, such as antelope horn granules.