The type of anemia that can reduce the hemaglobin level are the
microcytic-hypochromic anemia and the normocytic-normochromic
anemia.
Microcytic-hypochromic anemia produces small, abnormally small
erythrocytes and reduced hemoglobin concentrations. However,
hypochromia can occur even in cells of normal size. This type of
anemia results from a variety of conditions that are caused by
disorders of iron metabolism, porphyrin and heme synthesis, or
globin synthesis.
Normocytic-normochromic anemia produces a destruction or
depletion of normal or mature erythrocytes. Although the
erythrocytes are relatively normal in size and in hemoglobin
content, they are insufficient in number. This type does not share
any common cause, pathologic mechanism, or morphologic
characteristics and is less common than the others. The five
distinct anemic conditions exemplify the diversity of this
classification which are the aplastic anemia, posthemorrhafic
anemia, haemolytic anemia, anemia of chronic disease and sickle
cell anemia.