Low mean red blood cell hemoglobin content may be caused by thalassemia, iron deficiency anemia and iron granulocytic anemia. 1. Thalassemia: it is usually a chronic hemolytic anemia with impaired synthesis of the peptide chain of the pearl protein. Once it occurs, it will lead to the inability of hemoglobin synthesis, which will result in the low average red blood cell hemoglobin content. 2. Iron deficiency anemia: usually caused by iron deficiency, if the concentration of iron in the body decreases, it will lead to the lack of normal synthesis of hemoglobin by red blood cells in the bone marrow, thus causing the above phenomenon. 3. Iron granulocytic anemia: due to iron utilization disorder, red blood cells are ineffective in generating, resulting in low average red blood cell hemoglobin content. Once the index is abnormal, it is recommended that the patient should go to the regular hospital for consultation and treatment in time to avoid delaying the condition.