Generally, low platelet count requires bone marrow aspiration because low platelet count means the number of platelets is lower than the normal range. Clinically, there are many reasons for low platelet count, most of which are caused by hematologic diseases, the most common of which include immune thrombocytopenic purpura, myelodysplastic syndromes, and part of multiple myeloma, etc. These diseases require bone marrow aspiration to make a differential diagnosis; for example, immune thrombocytopenic purpura is the most common type of thrombocytopenia, in which bone marrow hemopoiesis can be found. All of these diseases require bone marrow aspiration to make a differential diagnosis; for example, immune thrombocytopenic purpura is the most common type of thrombocytopenia, and in bone marrow aspiration, it can be found that the bone marrow hematopoietic function is exuberant, and at the same time, there is an obstacle to the maturation of the development of megakaryocytes. In the case of low platelets caused by myelodysplastic syndromes, pathological hematopoiesis is also found, all of which are of clear significance for the diagnosis of thrombocytopenia. Therefore, all patients with low platelets need to have a bone marrow aspiration test to clarify the cause of the disease and avoid delays.