Increased platelet ratio refers to the number of platelets in the peripheral blood in the counted unit volume is higher than the high value of the normal range, which is categorized into primary increase and reactive increase. 1. Primary increase: the normal range of platelet specific volume is 0.18%~0.22%. Clinical diseases such as true erythrocytosis, early stage of primary myelofibrosis and primary thrombocythemia can cause primary increase of platelet. 2. Reactive increase: it is often seen in acute hemolysis, acute infection caused by factors that promote platelet production (interleukin-6, thrombopoietin, etc.) increased release, which leads to an increase in the specific volume of platelets. If the platelet specific volume is found to be higher than the high value of the normal range in daily physical examination, it is recommended to go to the hospital as soon as possible, and standardize the treatment under the guidance of the doctor, so as to avoid delaying the condition.