High PlateletsToday I received a laboratory report of a patient who had 1,093,000 platelets per micro liter which is well above the normal maximal level of 450,000 platelets.This is the first time that I have received such a high level of platelets in my 41 years of medical practice.I probably have to do further investigations on him before I can come to a conclusive diagnosis.However with such a high platelet count I probably should be worried about the coagulability of his blood and may need to give him a low dose of aspirin to prevent blood clot in his blood vessels.A high platelet count is 450,000 per micro liter or aboveA higher-than-normal number of platelets are called thrombocytosis or thrombocythemia.It means the body is making too many platelets.Causes may include:1. A type of anemia in which red blood cells in the blood are destroyed earlier than normal (hemolytic anemia)2. Anemia due to low iron3. After certain infections, major surgery or trauma, or allergic reactions4. Cancer5. Certain medicines6. Bone marrow disease called polycythemia vera7. Bone marrow making too many platelets without a known cause (primary thrombocytosis)8. Recent spleen removalSome people with high platelet counts may be at risk of forming blood clots.Blood clots can lead to serious medical problemsThrombocytosis or thrombocythemia is defined as a platelet count above the upper limit of the normal range (450 x 109 per micro liter in adults).The term thrombocythemia (or primary thrombocytosis) is preferred when the cause of a high platelet count is not known.When another disease or condition causes a high platelet count, the term thrombocytosis (or secondary thrombocytosis) is preferred.It is important to distinguish between true hematological disease causing primary thrombocytosis and secondary or reactive thrombocytosis caused by a physiological response to a primary problem.There are a number of hematological diseases causing primary thrombocytosis.Primary thrombocytosis is a chronic myeloproliferative disorder.However, there are other hematological diseases which can cause primary thrombocytosis, including1. Myeloproliferative neoplasms (MPNs),2. Myelodysplastic syndromes (MDS)3. Overlap syndromes.MPNs such as primary thrombocytosis (essential thrombocythemia), polycythemia vera and myelofibrosis are Philadelphia-negative clonal disorders of the bone marrow.Types of ThrombocytosisThere are broadly two types of thrombocytosis:Hematological disease such as primary thrombocytosisPrimary thrombocytosis (also referred to as essential thrombocytosis, essential thrombocythemia and primary thrombocythemia) is due to a failure to regulate the production of platelets (autonomous production) and is a feature of a number of myeloproliferative disorders.Features are a platelet count greater than 600 x 109 per micro liter, megakaryocyte hyperplasia, splenomegaly and a tendency to both thrombosis and hemorrhage.Platelet survival is normal but function is not.Other hematological diseases which cause primary thrombocytosis are myeloproliferative, myelodysplastic or a combination of both.It includes some leukemia.With primary thrombocytosis, a high platelet count may occur alone or with other blood cell disorders.Secondary or reactive thrombocytosisThis can be secondary to a number of conditions.When another disease or condition produces a high platelet count, the term "thrombocytosis" is preferred.This condition often is called secondary or reactive thrombocytosis.It is an exaggerated physiological response to a primary problem, such as an infection.TABLE OF CONTENTIntroductionChapter 1 High PlateletsChapter 2 CausesChapter 3 SymptomsChapter 4 DiagnosisChapter 5 TreatmentChapter 6 Prognosis... Dr. Kenneth Kee is a well-known medical doctor from Singapore who has been practicing medicine since 1972.He graduated from the University of Singapore and furthered his studies with a Master of Science in Health Management in 1991, followed by a Ph.D. in Healthcar
