Forms of anemia in which the average size and hemoglobin content of the red blood cells are within normal limits are called normocytic normochromic anemias. Usually microscopic examination of the red cells shows them to be much like normal cells. In other cases there may be marked variations in size and shape, but these are such as to equalize one another, thus resulting in normal average values. The normocytic anemias are a miscellaneous group, by no means as homogeneous as the megaloblastic anemias.
Anemia caused by the sudden loss of blood is necessarily normocytic at first, since the cells that remain in the circulation are normal. The blood loss stimulates increased production, and the young cells that enter the blood in response are larger than those already present in the blood. If the young cells are present in sufficient number, the anemia temporarily becomes macrocytic (but not megaloblastic). Treatment of anemia caused by sudden blood loss includes transfusion.