In infants with elevated leukocytes, bacterial infections are generally considered, and may be accompanied by fever, nausea, vomiting, diarrhea, so pay attention to whether it is a gastrointestinal infection; it may also be accompanied by coughing, coughing and other symptoms, so pay attention to whether it is a respiratory tract infection; or it may only have fever, so pay attention to whether it is a urinary tract infection; if the child has a poor mental state, poor response, easily irritable or drowsy, poor diet, and at the same time If the child has symptoms such as drowsiness and convulsions, a lumbar puncture should be performed to check for central nervous system infections. There are also some babies with increased leukocytes, along with fever, rash, red eyes, swollen lymph nodes and other manifestations, and the effect of anti-infection treatment is not good, then also consider whether Kawasaki disease. If the leukocytes are slightly elevated, but the baby has no other discomfort, it is also important to be highly suspicious of any underlying infection and to carefully check the body and monitor the blood count dynamically to avoid delays. After the birth of a newborn, there is a transient increase in leukocytes, which is a normal form of physiological manifestation and can be treated without treatment, for example, within 3 days of age the baby’s leukocytes can be above 20×109/L, which requires dynamic monitoring.