I hate to link to Vox, but the article actually made some good points.
I, and almost everyone I've ever talked to on the subject, have all agreed with the points in this article. Our blood pressure is almost always higher at the doctor's office than it is at home. In fact the only reason I bought a good monitor and started taking my blood pressure at home is because I so often got "hypertensive" readings at the doctor's office and was talked to about it.
My blood pressure for most of the years I've monitored it myself has averaged between 120-130 and 70-80. That's when I pretty much follow the procedures in the article. If I vary from it, or sometimes take it when I can about tell I'm tense, I've certainly seen it jump. I've also had readings at the doctor's office that were normal. More than 70% of the time though, I would have to say I'm higher when at the doctor. There was a time early on when I was getting higher values at home, and I think I could attribute that to a period of work stress, crappy eating not getting enough regular exercise. Nowadays though, it is always reliably in "healthy" values at home.
I think I can attribute the difference to many of the factors at the article. I may have just climbed the stairs to my doctor's office and been called in right away. The nurse may have put the cuff on over my shirt. The nurse may have me talking the whole time (almost always the case). I might be in a very uncomfortable chair in a very uncomfortable position while holding my arm up. Almost everything mentioned in the article happens to me at the doctor's office. Same with pulse. My normal resting pulse is in the low 60's, but more often than not is in the 70's or even 80's at the doctor's office. I think all because I haven't had a chance to "settle down" before the measurements are taken, or conversely, am riled up about something. :)
I think the changes can come even just walking from the waiting room (where I might have been sitting for 20 minutes - don't know if that is calmed down or riled up) to the back. In fact when I had my colonoscopy a few months ago, I was laying on the gurney hooked up to the monitoring equipment and the doctor was delayed, so I was calmly laying there awake for a good twenty minutes before they knocked me out. I was watching BP and pulse, and my BP was even dropping below 120 on the high and getting into the 60s on the low, and my pulse was in the 50s.
Anyway, I have to wonder how many people just take their BP value from the doctor at face value and end up on blood pressure meds? I was just thinking about this because I was talking to my cousin's wife a couple of days ago and she was on her way to her cardiologist with her home BP monitor and its history. He had been telling her that she was in denial on her BP because of the readings in his office.
https://www.vox.com/science-and-health/2018/7/3/17510132/new-blood-pressure-guidelines-ranges-hypertension