Hi welcome to HCm I have gone thru your query . Dear Kelly , I can understand your concern . One thing is sure that any medical condition doesn t come up without a cause and signs and symptoms are obvious to follow . Thrombocytosis is defined as a platelet count above the upper limit of the normal range .There are a number of haematological diseases causing thrombocytosis .It is an exaggerated physiological response to a primary problem, such as an infection , is caused by too much growth of a type of cell that is used to make blood cells It is an adverse prognostic factor in many types of cancer, including breast cancer, ovarian and other gynaecological cancers, renal cell carcinoma and lung cancer. The prognosis is usually be determined by the primary disorder. Hope this helps solves your query .Take care .All the best .Get well soon Don t hesitate to come back in case of any further query .