Re: how to keep your blood pressure down to pass a physical
Deep breathing shortly before the blood pressure is taken. Breathe in slowly, hold for three seconds, out slowly. Repeat several times.
Basically, when you are calm and physically relaxed, your breathing slows. Slowing down your breathing tricks your body into being calm.
Of course, if you do have high blood pressure, lowering it for the test isn't going to solve it in the long run.