What do elevated eosinophils in the blood mean?

May be a warning: An absolute eosinophil count above 500, especially in the morning, deserves some attention. Despite "pop" wisdom, it's seldom a warning about allergy, and if your allergies are acting up, you'd know anyway. Anything from worms to hodgkin's to the eosinophil family of diseases to nothing-at-all can do this. Again, the history & physical exam is your key. Best wishes.