Children’s fever blood high, usually refers to the white blood cells and other indicators of increased, can be seen in respiratory tract infections, infectious diarrhea disease, Kawasaki disease, acute leukemia and other diseases, need to be analyzed on a case-by-case basis. 1. Respiratory tract infections: such as bronchopneumonia caused by bacterial infections, fever can occur, accompanied by coughing and wheezing and other symptoms, both lungs can be detected in the examination of fine wet rales, perfect auxiliary examination can be seen in the indicators of infection, such as leukocytes and other indicators of increased, that is, the high blood picture. 2. Infectious diarrhea disease: such as diarrhea disease caused by Escherichia coli, often manifested as fever, accompanied by an increase in the number of stools and changes in the nature of the stools, some children may be accompanied by vomiting, perfect stool routine can be seen in the leukocytes, blood routine can be seen in the leukocytes and other increased. 3. Kawasaki disease: clinical recurrence of fever, accompanied by rash, cracked lips and mouth, or hard swelling of the hands and feet, etc., perfect blood test can be seen in the peripheral blood leukocytes increase, mainly neutrophils, that is, high blood manifestations. 4. Acute leukemia: these children may have fever, variable fever, accompanied by pallor, dysphoria, enlarged liver, spleen and lymph nodes, etc., perfect peripheral blood picture, some children can see increased leukemia, often accompanied by a decrease in blood cells and hemoglobin. It is recommended to consult a specialist to determine the cause of the disease and provide targeted treatment.