Leukocytes are the immune cells in our body. When a child has an increase in leukocytes, it may be due to physiological factors or pathological reasons. Physiological factors: When the child has eaten, or after playing, playing games, or strenuous exercise, there will be a physiological increase in white blood cells, parents should not be too afraid and alarmed, these will not affect the baby. In addition, if the site of the blood draw is different, it may also lead to a deviation in the number of white blood cells. Pathological factors: pathological leukocyte increase is something that we need to pay great attention to, commonly bacterial infection, EBV infection, tissue damage or necrosis, allergic reactions, toxic reactions, blood disorders, etc. The appearance of these diseases can cause an abnormal increase in leukocytes, and also cause serious impact and harm to human health, so once found to be caused by these reasons, it is necessary to actively take Therefore, once these causes are detected, it is necessary to take active treatment measures. Therefore, regardless of whether the increase in white blood cells in children is physiological or pathological, it is necessary to pay great attention to and be vigilant, and to cooperate with doctors for timely examination and treatment.