Editing Anemia (section)

===Red blood cell size===
In the morphological approach, anemia is classified by the size of red blood cells; this is either done automatically or on microscopic examination of a peripheral blood smear. The size is reflected in the [[mean corpuscular volume]] (MCV). If the cells are smaller than normal (under 80 [[femtolitre|fl]]), the anemia is said to be [[microcytic anemia|microcytic]]; if they are normal size (80–100 fl), normocytic; and if they are larger than normal (over 100 fl), the anemia is classified as [[macrocytic anemia|macrocytic]]. This scheme quickly exposes some of the most common causes of anemia; for instance, a microcytic anemia is often the result of [[Iron deficiency (medicine)|iron deficiency]]. 

In clinical workup, the MCV will be one of the first pieces of information available, so even among clinicians who consider the "kinetic" approach more useful philosophically, morphology will remain an important element of classification and diagnosis.
Limitations of MCV include cases where the underlying cause is due to a combination of factors – such as iron deficiency (a cause of microcytosis) and vitamin [[B12 deficiency]] (a cause of macrocytosis) where the net result can be normocytic cells.{{medical citation needed|date=January 2016}}