My platelet count is very high (825). i'm taking 25mg teva-hydrochlorothiazide tablets & asa 8mg baby aspirin tablets. would these medications help lower it? i get tested every 3 months & it keeps rising. also, would a blood transfusion help?

Hctz does not lower platelet count, neither do ASA and blood transfusion; however, ASA may be helpful with anti-platelet effect in the coagulation cascade. There are means (medications and procedure) for treating thrombocytosis (high platelet count) but you do not need it yet with the current number. Please do not worry much and continue to follow with your doctor(s).