Children who only have fever without any symptoms may be caused by the early stage of infectious diseases, autoimmune reaction, non-infectious fever and other conditions. 1. Early stage of infectious disease: In the early stage of the disease, other symptoms are not shown except fever. 2. Autoimmune reaction: Children with autoimmune reaction may also have fever without other symptoms, so if they have no other symptoms, they can be observed first. 3. Non-infectious fever: mainly due to tissue destruction or necrosis, connective tissue diseases, metabolic reactions, temperature center dysregulation, etc., can also lead to the phenomenon of children only fever without any symptoms. When a child has a fever without any symptoms, it is recommended that the patient go to a regular hospital in time to avoid delaying the condition.