Low hemoglobin and platelets can be seen in a variety of conditions, and common causes include megaloblastic anemia, aplastic anemia, and immune thrombocytopenia. 1. Megaloblastic anemia: due to the lack of folic acid and vitamin B12, which are the raw materials for hematopoietic production, it affects the development and maturation of megakaryocytes, resulting in platelet reduction and hemoglobin reduction. 2. Aplastic anemia: often with low platelets and clinical bleeding symptoms. In addition to low platelets, low white blood cells and hemoglobin are often combined. Bone marrow image often suggests that myeloproliferative hypoplasia is present, and cells of various lineages are reduced. 3. Immune thrombocytopenia: it is the most common hemorrhagic disease in pediatrics. Its main clinical features are spontaneous bleeding from skin and mucous membranes, thrombocytopenia, prolonged bleeding time, bleeding is not serious, there is usually no change in red and white blood cells; when bleeding is serious, red blood cells and hemoglobin decrease. Low hemoglobin and platelets may also be seen in other diseases, such as acute leukemia, etc. Therefore, it is recommended to go to the regular hospital in time, complete the relevant examination by the specialist to make a judgment.