Anemia can be classified according to the morphological characteristics of red blood cells into macrocytic anemia, normocytic anemia, and microcytic hypochromic anemia. The diagnosis of macrocytic anemia includes a mean red blood cell volume greater than 100fL and a mean red blood cell hemoglobin concentration between 32%-35%. Common diseases associated with macrocytic anemia include megaloblastic anemia, hemolytic anemia with extensive reticulocytosis, myelodysplastic syndromes, and liver diseases. Microcytic hypochromic anemia, on the other hand, is diagnosed when the average red blood cell volume is less than 80fL and the average red blood cell hemoglobin concentration is less than 32%. Common diseases associated with microcytic hypochromic anemia include iron deficiency anemia, sideroblastic anemia, and thalassemia.