The difference between iron deficiency anemia and megaloblastic anemia is very obvious, their average erythrocyte volume and average hemoglobin concentration are different, as well as the results of the three anemia tests are different, as follows: 1. The average erythrocyte volume is different: you can judge by the average erythrocyte volume and average hemoglobin concentration. Iron deficiency anemia is a small cell hypochromic anemia, and the average volume and average hemoglobin concentration of red blood cells are lower than the lower limit of normal value, while megaloblastic anemia is a large cell anemia, and the average volume and average hemoglobin concentration of red blood cells are higher than the upper limit of normal value. 2. Different results of the three anemia tests: The three anemia tests can be used to distinguish between iron deficiency anemia, where there is a significant decrease in ferritin, and megaloblastic anemia, where there is folic acid and vitamin B12 deficiency. vitamin B12 deficiency.