Platelet increase in children can be a physiological phenomenon, but also can be pathological factors caused. 1, physiological reasons: increased platelets in children, sometimes a physiological phenomenon, the general physical examination of blood routine, will find high platelets, but generally will not be significantly higher than the normal value, only slightly higher than a little, the child also has no performance, this situation is not the need to do special treatment, regular monitoring can be. 2, pathological reasons: another reason for the increase in platelets is pathological changes. The more common are secondary factors, such as secondary to infection, whether respiratory tract infection, gastrointestinal tract infection, etc. may cause platelet elevation, the degree of elevation varies, if significantly elevated need to promptly seek medical attention, may need some drug treatment; Kawasaki disease is a feature of platelet elevation, after treatment is generally can also be improved; thrombocytosis is a myeloproliferative disease, if necessary, need to perform bone marrow If necessary, a bone marrow aspiration is required. If the platelets are elevated in children, it may lead to platelet aggregation and blood hypercoagulation, which may lead to blood clots. Therefore, it is necessary for children with elevated platelets to consult a doctor promptly to determine the cause of elevated platelets and whether treatment is needed.