The real problem is that these stupid new automatic devices have wildly-varying results... truly all over the map. And they’re laughable when the batteries are anywhere near weak.
I’ve found that those *&#^@ machines ALWAYS read too high and I’ve had plenty of nurses tell me so.
When I get a manual, done by a real human being, blood pressure, it’s almost always close to my usual.
When they use that blankety-blank machine, it adjusts the pressure and about squeezes my arm off and takes FOREVER to deflate.
And they wonder why it reads high.
And then of course, they show concern and start talking blood pressure meds.
What I finally did with my PCP was told her to look at the readings from my allergy shots and when she did, she dropped the subject.
For these and other factors the best method IMO is aggregation of data; several readings across different days/times to discern the average and median.
My Mom has an Omron, supposedly they are “the best” eh, they are OK, she checks her blood pressure a few times a day since she has high blood pressure, she always adds another 10 points since she knows its not accurate..for me its always wrong, I have small arms sometimes it doesnt read at all and yes the batteries weak signal is annoying its been blinking for weeks now but the machine still functions