Just left the er for high bp bc my dr. stop beta blocker without weaning and started an arb. all labs look good but wbc is 12.2 , the diff showed high gran # 7.5 (range to 6.5) and high lymph # 3.9 (range to 3.9). what could this be?

It is possible that it is reactive from abnormally high blood pressure, or you may be recovering from a minor infection that your body is taking care of -- you may not have even have had clinical symptoms (the body is neat like that). Would consider getting another CBC with differential in a week or two to recheck the parameters. Best wishes.