I never had any symptoms, just every year my platelets went higher for 3 years in a row. The best diagnosis is a bone marrow biopsy and bone marrow aspiration. There are many sub-groups under MPN (myeloproliferative neoplasm) I would suggest you go to a MPN specialist usually a major medical/teaching hospital. You need to get a second opinion if your O/H doesn't know, and even if they know it is good to get a second opinion. My oncologist said platelet counts can vary from morning to night, but if the trend is going up, over normal range good to get that second opinion. Elevated platelets can result in heart attack or stroke as they form clots, not a good thing. I found the Leukemia Lymphoma Society website and excellent webside for information.