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What is Polycythemia?

  • Polycythemia is a rare blood disorder that occurs when there are too many red blood cells circulating in the bloodstream. Red blood cells carry oxygen from the lungs to all parts of the body. Polycythemia causes the blood to thicken, making it more difficult for the blood to flow through the body to the organs.

    Polycythemia can be divided into two overarching categories:

    • Primary polycythemia, caused by overproduction of red blood cells by the bone marrow, due to mutation or biological factor in the body.
    • Secondary polycythemia, which is caused by factors that reduce the amount of oxygen reaching the body's tissues, such as smoking, high altitude, or congenital heart disease. The red blood cells in some patients with secondary polycythemia may carry an abnormal form of hemoglobin that does not release oxygen readily (high-affinity hemoglobin)

    Polycythemia Treatment at Dana-Farber/Boston Children's

    Children with polycythemia are treated at the Blood Disorders Center within the Dana-Farber/Boston Children's Cancer and Blood Disorders Center, where children and young adults receive care from pediatric hematologists with deep experience in the conditions they treat.

    Learn more

    Find more in-depth information on polycythemia on the Dana-Farber/Boston Children's website, including answers to:

    • What is polycythemia?
    • What are the symptoms of polycythemia?
    • How is polycythemia in children diagnosed?
    • How is polycythemia in children treated?