Bone marrow aspiration can be used for differential diagnosis or exclusion of leukemia, aplastic anemia, paroxysmal sleep hemoglobinuria, etc. Bone marrow aspiration is a very safe test with little chance of serious bleeding, infection or serious complications. However, there are some precautions to be taken after bone marrow aspiration for patients with thrombocytopenia, such as local wound compression for an appropriate length of time after the aspiration, usually 20-30 minutes of local pressure, which is more conducive to local wound hemostasis. The patient should also be kept in the hospital for observation for a longer period of time to observe whether the bleeding tendency is very obvious. If there is an obvious bleeding tendency, consider that the patient should be hospitalized in a timely manner for treatment without waiting until the results of the bone marrow aspiration are returned. Bone marrow aspiration examination can clarify the underlying cause of thrombocytopenia.