If you are getting regular check ups and blood work, blood pressure is but one of several metrics. If you are cruising along fine, and then all of a sudden there is a change—that is a signal.
As single metric is never a good reason to do much. You have to understand how the machines works and all of the parts that go into it.
Someone needs to tell the doctors. Their standard M.O. seems to be get the blood pressure, look at a chart, and if x>y, write a scrip.