Polycythemia

Virginia C. Broudy, MD

University of Washington School of Medicine, Seattle, WA

This case was reviewed and updated in October 2010 by Dr. Eric Kraut and members of the Teaching Cases Study.

Copyright of the American Society of Hematology, 2006. ISSN: 1931-6860.

V. PATHOPHYSIOLOGY

Major Pathophysiologic Categories of Polycythemia

Relative Polycythemia (Gaisbock's Syndrome)
  • Red blood cell mass is normal.
  • Plasma volume is decreased.
  • The use of diuretics to treat hypertension may further decrease plasma volume.
  • A high carboxyhemoglobin level due to smoking may also play a role.
  • Affects predominantly men (M:F ratio 10:1) who are middle aged (45-55 years old) and are smokers.
  • May affect approximately 0.5-0.7% of the adult male population in the USA.
Secondary Polycythemia Can be due to one of these causes:
  • an appropriate increase in erythropoietin production as a result of tissue hypoxia.
  • an inappropriate increase in erythropoietin production as a result of renal or (rarely) hepatic disorders. (Click here for more information on erythropoietin production and tissue hypoxia.)
Polycythemia Vera
  • Overproduction of red blood cells and often overproduction of white blood cells and platelets.
  • Neoplastic disorder that originates in a hematopoietic stem cell. (See V. PATHOPHYSIOLOGY for a stem cell model of hematopoiesis.)

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