Regarding white coat hypertension, the shot isn’t always necessary. Some people’s blood pressure just goes up from the stress of the clinical setting.
I had a doc appointment a couple of weeks ago. My wife was driving and we were running late, so I was getting stressed about missing the appointment on top of being stressed about going to see the doctor. There was a lot of traffic so I decided to get out at a red light and run to my appointment while my wife parked the car. I only barely made it and the first thing they did was take my pressure. They took it twice, because at the first they were like, this can't be right. When I explained, they asked if I had a blood pressure monitor at home so I could take my own pressure at a more quiet moment.
The guidelines for taking blood pressure state you should be sitting quietly for 5 minutes beforehand, something that almost never happens at the doctor's.