Polycythemia

An abnormal increase in the concentration of red blood cells or hemoglobin.

Causes

• Polycythemia vera: A clonal/myeloproliferative disorder

• Hypoxia

  • High-altitude residence

  • Chronic smoking

  • Chronic obstructive pulmonary disease (COPD)

  • Obstructive sleep apnea

  • Chronic hypoxemic lung disease

  • Cyanotic congenital heart disease

• Secondary erythropoietin-mediated causes

  • Polycystic kidney disease with increased erythropoietin production

  • Erythropoietin-producing tumors (renal cell carcinoma, hepatocellular carcinoma, cerebellar hemangioblastoma)

  • Exogenous erythropoietin therapy

• Medications

  • Testosterone and other anabolic steroids

  • Corticosteroids (less commonly)

  • Diuretics

• Hypovolemia: Apparent polycytemia due to volume depletion/burns/dehydration