Dealing with Polycythemia in Primary Care

hematocrit and hence the red cell mass is persistently elevated. After ruling out the presence of spurious polycythemia, attention should be focused on the causes of true polycythemia, namely primary and secondary polycythemias. Primary polycythemias are disorders in which the erythroid progenitors are hypersensitive to very low levels of erythropoietin while secondary polycythaemias are characterized by an increased red cell production owing to a physiologic response to hypoxia or to a deranged and exaggerated production of erythropoietin (Table 1).