I tend to suffer from "white coat fever". Meaning, put me in a medical office setting, and although I don't feel any conscious nervousness, my BP will spike. Oftentimes, upward of 170/80. Take my BP at home, it's usually around 130/80.
Yesterday was a classic example. Went to the VA hospital, for some outpatient surgery (removal of a sebaceous cyst, on my back). I'm relaxed (and well numbed) while the PA and his student are doing the procedure to remove it. But the BP showing on their machine is up around 170/80. The RN asked me if I took blood pressure medication, and I explained my issue.
Sure enough, by the end of the procedure, as they're putting the pressure dressing over the incision area, my BP is back down to 135/75. Go figure!