Polycythemia
abnormal increase in the number of red cells in the blood due to excess production of these cells by the bone marrow
Two categories of polycythemia
1. Relative2. Absolute
what is relative polycythemia?
Elevated red cell due to dec. plasma volume (hemoconcentration): Dehydration, Gaisbock syndrome (stress polycythemia)
what is absolute polycythemia
there is true elevation or increased in red cell production. may be primary or secondary
what is primary polycythemia (absolute)
increased in red cell production, independent of erythropoietin. Polycythemia vera is the common cause
what is secondary polycythemia vera (absolute)
increased in red cell production due to elevated erythropoeitin1. Physiologic inc (Lung disease, high altitude, cyanotic heart disease) note: low 02 stimulates EPO2. Pathologic (erythropoietin secreting tumor (renal or hepatocellular)