left arm - right arm differential
For years I had my bp checked on an irregular basis by the same nurse at work. She always, always took my bp on my left arm. It was pretty consistent around 110/70. I changed jobs a few years ago and just didn't bother with getting anything checked - felt perfectly healthy (don't bother lecturing about the need for regular checkups, my new doctor has already done that). Anyway, to the point, when I started getting my bp checked again a couple of months ago the systolic reading on my right arm was 20 points higher than on my left arm. Diastolic reading differential was less dramatic, about 7 points lower on the left. This was consistent for 8 weeks, then the differential flipflopped. Now systolic reading on my left arm is 10 points *higher* than on my right, while the diastolic number is equal. When I first started going to the doctor, she suggested that the right arm measurement should be taken as the benchmark, since it was the higher of the two. On average, my bp is now "high normal", still high on one side, ok on the other. Which, if any, is the one to go by?