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Essential thrombocythemia

Other Names for this Disease
  • Essential thrombocytosis
  • Hemorrhagic thrombocythemia
  • Idiopathic thrombocythemia
  • Primary thrombocythemia
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Essential thrombocythemia belongs to a group of conditions called myeloproliferative disorders. Myeloproliferative disorders cause platelets, white blood cells and red blood cells to grow abnormally in the bone marrow (the soft tissue inside the hollow part of bones that helps form blood cells). In essential thrombocythemia, the body produces too many platelet cells. The signs and symptoms vary from person to person, with up to two-thirds of patients not having any symptoms when the platelet cell count first increases. Signs and symptoms may include significant increased production of megakaryocyte (a cell in the bone marrow that is responsible for making platelets), enlargement of the spleen (splenomegaly), and bleeding and/or clotting episodes.[1][2]
Last updated: 6/30/2011


  1. Primary thrombocythemia. MedlinePlus Medical Encyclopedia. February 28, 2011; Accessed 6/30/2011.
  2. Essential Thrombocythemia. National Cancer Institute. March 2010; Accessed 6/30/2011.
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Basic Information

  • The CMPD Education Foundation provides online information on myeloproliferative disorders (MPD). Click on the link to view the resource.
  • Genetics Home Reference (GHR) contains information on Essential thrombocythemia. This website is maintained by the National Library of Medicine.
  • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.
  • The Merck Manuals Online Medical Library provides information on this condition. Click on the link to view the information.
  • The National Cancer Institute provides the most current information on cancer for patients, health professionals, and the general public.  Click on the link to view information on this topic. 
  • The National Organization for Rare Disorders (NORD) is a federation of more than 130 nonprofit voluntary health organizations serving people with rare disorders. Click on the link to view information on this topic.

In Depth Information

  • Medscape Reference provides information on this topic. Click on the link to view this information. You may need to register to view the medical textbook, but registration is free.
  • The Online Mendelian Inheritance in Man (OMIM) is an catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs.  Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Essential thrombocythemia. Click on the link to view a sample search on this topic.