It does not determine whether a mean platelet volume of 5.9fl is important or not, but only indicates the presence of a low mean platelet volume, which needs to be combined with the number of platelets to make a judgment on it, and is usually not particularly important. Mean platelet volume refers to the average volume of each platelet in the peripheral blood, and its normal value is between 7 and 11fl. If the mean platelet volume is 5.9fl, it means that the mean platelet volume is low, which indicates that the bone marrow hematopoietic ability of the patient is reduced. It may be related to many factors, such as malnutrition, gastrointestinal bleeding, viral infection and aplastic anemia or leukemia. 1. Generally speaking, a simple low average platelet volume does not mean anything and is usually not particularly important, the specific situation should be judged in conjunction with the number of platelets. If the drop in platelet count is small, then no special treatment is needed for the time being. 2. However, if the platelet count continues to drop and becomes seriously low, then further examination should be conducted as soon as possible to clarify the cause, which can be seen in aplastic anemia, primary immune thrombocytopenia, acute leukemia, etc.. Patients should be clearly diagnosed under the guidance of the doctor, standardized treatment, do not self-medication, so as not to miss the best time for treatment, resulting in further aggravation of the condition.