====== Essential thrombocythemia ====== Essential [[thrombocythemia]], Is a rare blood disease in which the [[bone marrow]] produces too many [[platelet]]s. High numbers of platelets may lead to a [[thrombus]], a blood clot that forms in a blood vessel. This can cause serious health problems such as a stroke, heart attack, or [[pulmonary embolism]]. [[Polycythemia vera and essential thrombocythemia combination]]