Polycythemia vera is defined as a condition in which the hematocrit exceeds 50%. There are two causes: relative, in which plasma volume has decreased but red cell mass is preserved; or absolute, in which red cell mass is increased regardless of plasma volume. Absolute #polycythemia may be reactive, as in heavy smokers, or may indicate a myeloproliferative disorder, polycythemia rubra vera.
- These patients typically present with malaise, fever, ruddy complexion (plethora), and pruritus after a warm shower. Some will also have cardiovascular symptoms (stroke, MI, claudication, headache) as a result of vascular congestion. Splenomegaly is a common finding in these patients.
- Primary polycythemia is idiopathic and is commonly referred to as polycythemia vera. Remember the symptoms with the #mnemonic Polycythemia Rubra Vera (PRV): Plethora/Pruritus, Ringing in ears, and Visual blurring. Secondary polycythemia is associated with oxygen deprivation, as in the setting of COPD or other lung diseases, high altitudes, erythropoietin-producing tumors, or smoking (an increase in carboxyhemoglobin)
Hope that helped. Let us know in the comments below.
Also check out these medical mnemonics