←back to thread

330 points wglb | 1 comments | | HN request time: 0.302s | source
Show context
crazygringo ◴[] No.41841006[source]
There's definitely a huge variance in blood pressure readings depending on posture, relaxation, arm position, recent activity, etc. If you buy a blood pressure monitor, it's really interesting to see how "random" a single reading at the doctors' is, and how large your fluctuation throughout the day is.

That being said, it really makes me wonder about studies that correlate blood pressure with other things. Is the blood pressure really being measured "correctly" in all those studies? Or not?

In other words, if your "true correct" blood pressure is lower than what the doctor normally takes, but then a lot of the studies are based on real-life "incorrect" higher blood pressures, then don't you similarly want an "incorrect" higher reading for consistency? Or are the studies always really done with far more accurate blood pressure readings, where the patient sits still for 5 min beforehand, keeps their legs uncrossed, is totally free of stress and anxiety, didn't exercise beforehand, etc.?

replies(18): >>41841065 #>>41841066 #>>41841097 #>>41841378 #>>41841596 #>>41842242 #>>41842355 #>>41842512 #>>41842978 #>>41842987 #>>41843132 #>>41843291 #>>41843843 #>>41843882 #>>41844009 #>>41844704 #>>41845158 #>>41848507 #
1. lo_zamoyski ◴[] No.41848507[source]
Yes, I was thinking the same. If everyone is measuring heart rate under similar conditions, and then correlating that heart rate with other factors, is that perhaps alright? Can we factor out the "error" to get a working baseline, even if the measurement isn't really heart rate at rest?

I doubt it, frankly. No one is controlling for these conditions. The easiest thing you can do is to wait a few minutes for the patient to relax after entering the examination room to get a reading at rest.