Normal platelet value: (100 to 300)×10^9/L.

When the platelet count is >400×10^9/L, it is thrombocytosis. Essential thrombocythemia is common in myeloproliferative diseases, such as chronic myelogenous leukemia, polycythemia vera, and primary thrombocythemia. Thrombocytosis, etc. Thrombocytosis is common in patients with acute and chronic inflammation, iron deficiency anemia and cancer. This increase generally does not exceed 500×10^9/L. After treatment, the situation improves and the number of platelets will soon drop to normal. level.

High platelets can be caused by many conditions, but generally there are two conditions: (1) Physiological. Normal people’s platelets generally change by 6%-10% a day, and are lower in the morning. , slightly higher in the afternoon; lower in spring, slightly higher in winter; higher in plateau areas; higher after menstruation; higher after exercise. ⑵ Pathological myeloproliferative diseases, essential thrombocythemia, acute hemolysis, acute purulent infection, etc. can all cause elevated platelets.

For a 14-year-old girl, the platelet count of 309 is not too high. People with slightly higher than normal values ??will generally not have problems if other values ??are normal and there are no symptoms.