Causes of Elevated Red Blood Cell Levels (Erythrocytosis)

Classification and Clinical Implications

• Elevated red blood cell levels can be classified into primary and secondary causes, with primary causes stemming from intrinsic defects in red blood cell progenitors and secondary causes resulting from factors external to the erythroid compartment, according to the Mayo Clinic Proceedings 1
• True polycythemia is characterized by an actual increase in red blood cell mass, which can be either clonal or non-clonal, as noted in the Mayo Clinic Proceedings 1
• Apparent polycythemia is a spurious increase due to reduced plasma volume without actual increase in red blood cell mass, as described in the Mayo Clinic Proceedings 1
• Inapparent polycythemia is a true increase in red blood cell mass masked by normal hemoglobin/hematocrit values due to concurrent increase in plasma volume, according to the Mayo Clinic Proceedings 1
• Smoking can lead to smoker's polycythemia, a form of secondary erythrocytosis, as reported in the Mayo Clinic Proceedings 1
• Microvascular disturbances, including erythromelalgia, are a clinical implication of polycythemia vera, as noted in the Mayo Clinic Proceedings 1