The white blood cells in the blood are the body’s patrols to defend against bacterial invasion. When foreign substances such as bacteria invade, the white blood cells enter the invaded area and surround and devour and destroy the bacteria and other foreign substances. When a newborn baby is born, the total number of white blood cells is much higher than that of an adult. This is to adapt to the change in the environment, as the baby faces the loss of protection from the womb and the invasion of harmful substances in nature, so the white blood cells must be raised to enhance the resistance to the outside world. The normal value of white blood cells in newborns is (15.0-20.0) × 109/L, but when the degree of increase in white blood cells is significantly abnormal, that is, the value is higher than 20.0 × 109/L may have suffered an infection, the reason for the abnormal increase in white blood cells at this time is because there is inflammation somewhere in the body, the body makes self-protection measures to increase white blood cells to devour harmful bacteria, so the medical science used This principle is used in medicine to verify that the body is not inflamed or damaged, such as neonatal pneumonia, sepsis, etc. In short, elevated white blood cells in newborns must be distinguished as a physiological or pathological phenomenon, and if the white blood cells are abnormally elevated, you must seek medical attention and active treatment in a timely manner.