Children’s blood routine can be looked at in the following major ways: 1. You can look at the level of white blood cells in the blood routine because the white blood cell count in children is within a certain range. If the white blood cell count is significantly elevated, it is mostly due to a bacterial infection. If it is a viral infection, the white blood cell level in children’s blood tends to be normal or low. 2. You can look at the ratio of neutrophils, because the composition of children’s white blood cells is mainly neutrophils. If neutrophils are high, they tend to be consistent with the level of white blood cells, and elevated neutrophils are often also due to bacterial infections.3. You need to look at the child’s platelet count, which also has a range. If it is significantly low, it can cause bleeding in children. If the platelets are high, it can cause a hypercoagulable state.4. You can look at the child’s hemoglobin. If the hemoglobin is low, it often indicates anemia.