Don't assume your will have side effects from Hydrea. My platelets were 600s for 10 years and hemotologist just watched it. No treatment. Then I ended up in hospital with serious pulmonary embolisms. New hemotologist tested for JAK2 and it was positive. Immediately began 500 mg of Hydrea daily. Now in normal range with no side effects BUT I do have serious condition resulting from the PEs. Do what needs to be done to prevent PEs!!!!!!!!