[atahanacar]

Literally the first year of medical school, we were taught to let the patient rest for at least 5 minutes before taking vitals, while also asking about recent exercises or caffeine intake. This reduces the likelihood of a mistake, but white coat hypertension is still a thing. That's why we also teach them/relatives how to correctly measure BP on their own and ask them to measure it at home, preferably after waking up before eating anything.

[ajuc]

My wife has one specific guy doing the measurement that she hates and when he measures her pressure it's like 10-20 higher.

It's also the guy that measures pressure before letting people enter to the cryo chamber, so she spend about a week rescheduling and arguing with him to let her in.

When she went to another person at the hospital her pressure was perfectly fine, and switching the instruments didn't helped - if THE guy measured it - it was too high - when it was somebody else - it was OK, no matter the instrument used :)

[atahanacar]

Definitely possible. Blood pressure fluctuates during the day. Activation of the sympathetic nervous system causes the BP to increase. So technically the measurements were "correct", but it was misleading because when talking about BP we normally mean "resting BP".

[standardUser]

No doctor or assistant bothered to tell me about the impact of caffeine. I had a few borderline-high readings over a few months and was concerned until I realized I was drinking my normal 2-3 cups of highly caffeinated coffee just before these visits.