I have received my results from my blood tests after 4 weeks on 500 mg. of Hydroxyurea. The first week went from 891 to 790 then down to 689 but the latest result was an increase to 700. I had another blood test done today (being done every week) but won't know the result for a while. Do you think I should be concerned about the elevation? Is this just a fluke, or am I becoming accustomed to the drug, and it is no longer going to be effective, at least at this level? I know these are questions for my haematologist, but I hope maybe there is some anecdotal evidence that you might be able to share with me. (I have no appointment until October.....but should I call? I don't know)