What is polycythemia?

Polycythemia is a blood disorder occurring when there are too many red blood cells, which carry oxygen from the lungs through the blood stream to the rest of the body. The excess red blood cells cause the blood to increase in volume and thicken, keeping it from flowing easily.

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).

There are three forms of primary polycythemia:

  • polycythemia vera or primary bone marrow polycythemia, an adult disease of the blood-forming hematopoietic stem cells
  • primary familial and congenital polycythemia, caused by genetic abnormalities or inappropriate levels of a hormone called erythropoietin (which triggers red blood cell production)
  • newborn polycythemia, which is detected before or at birth and treated in a neonatal intensive care unit

How we care for polycythemia

Children with polycythemia are treated at the Blood Disorders Center at Dana-Farber/Boston Children's Cancer and Blood Disorders Center where children and young adults receive care from some of the world’s most experienced hematologists with deep experience in the conditions they treat. 

Our areas of research for polycythemia

New medications for adult polycythemia vera are currently in development. The results of these efforts, as well as of studies of the biology of adult polycythemia vera, may one day benefit children with other forms of polycythemia.

Clinical trials

For many children with rare or hard-to-treat conditions, clinical trials provide new options. Search our clinical trials database. If you’re not sure which clinical trials might be right for your child, email us at clinicaltrials@danafarberbostonchildrens.org. We can help you navigate your options.