Children’s fever is considered to be related to pneumonia, tonsillitis, chicken pox, leukemia, etc. Common symptoms include cough, sore throat discomfort, body weakness and so on. 1. Pneumonia: Pneumonia is related to bacterial, viral and other pathogenic infections. In addition to fever, children are prone to coughing, coughing up phlegm, generalized pain, loss of appetite, shortness of breath, chest pain and other symptoms. 2. Tonsillitis: the disease is related to infectious factors, immune factors, acute inflammation of nearby organs, which can cause fever and high white blood cells in some children. Some children are also susceptible to pharyngeal pain and discomfort, chills, refusal to eat, crying, dysphagia, dyspnea and other symptoms. 3. Chickenpox: Chickenpox can cause fever in some children. Chickenpox is related to varicella-zoster virus infection, and is easily accompanied by red spots, papules, weakness, loss of appetite, cold and other symptoms. 4. Leukemia: the cause of leukemia is not completely clear, may be related to physical factors, genetic factors and so on. The disease will cause the child to have a fever, but also easily accompanied by pallor, swollen lymph nodes, skin ecchymosis, joint pain and other symptoms. There are many causes of fever in children, such as measles and colitis. Further detailed examination is recommended in order to clarify the cause of the illness and then follow the doctor’s instructions for treatment.