What is polycythemia?

Also known as: Polycythemia vera, primary polycythemia, secondary polycythemia, newborn polycythemia, PFCP.

Polycythemia is a rare and serious blood disease that causes the bone marrow to produce too many red blood cells to circulate in the blood stream. This causes the blood to become thicker, makes it more difficult for blood to flow throughout the body, and can lead to blood clots. 


Polycythemia can be divided into:

  • Primary or intrinsic polycythemia
  • Secondary or extrinsic polycythemia


Primary polycythemia has three forms:

  1. Newborn polycythemia
  2. Primary familial/congenital polycythemia (PFCP)
  3. Polycythemia vera

Secondary polycythemia may be congenital (e.g.hemoglobin variants) or acquired.


Reviewed by: Jack Wolfsdorf, MD, FAAP

This page was last updated on: 1/29/2019 3:21:13 PM

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