Secondary Polycythemia Follow-up

Updated: Jul 20, 2020
  • Author: Srikanth Nagalla, MD, MS, FACP; Chief Editor: Sara J Grethlein, MD, MBA, FACP  more...
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Excessive polycythemia, usually defined as hematocrit levels higher than 65-70%, may result in increased whole blood viscosity. This, in turn, may lead to impaired blood flow locally, resulting in thrombosis. Hyperviscosity may also lead to generalized sluggish blood flow, resulting in impaired tissue oxygenation in multiple organs, which may lead to decreased mentation, fatigue, generalized weakness, and poor exercise tolerance.



The prognosis of patients with secondary polycythemia is generally related to the prognosis of the underlying disorder. However, the polycythemia itself, when physiologic and not sufficiently extreme to cause significant hyperviscosity, is generally associated with a normal life span. However, emerging evidence suggests that at a minimum, patients with congenital or familial primary polycythemia may have an increased risk of thrombosis.