- Microcytic: Iron deficiency (blood loss, inadequate iron absorption), lead toxicity, Thalassemia (w/trait: low mcv w/relatively preserved HgB), other
- Microcytic =s MCV < 80
- Iron deficiency: microcytic, hypocrhomic, low retics, low iron, low transferrin saturation, low ferritin
- Thalassemia: with trait, low MCV (e.g. < 70), with relatively preserved hemoglobin
- Lead: Low MCV with normal iron, transferrin, iron saturation