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.?
> Is the blood pressure really being measured "correctly" in all those studies? Or not?
This is why you do readings three different times a day for several days. And why there’s instructions on how long to dust still before the readings, why you do three repeats with multiple minutes of wait in between, and finally why the averages of those readings aren’t just simple averages. But yes you always have to wonder about every study using self reported home readings if they follow the instructions or not, because it is tedious to do it correctly.
You might be surprised. "White coat hypertension" is well-known. Someone with a reliable set of readings from home would be more convincing than someone who says "I get it read at Walmart/CVS once a month and it's ok".
Your doctor's office's monitor isn't incredibly accurate. If you want accurate, you need a mercury sphygmomanometer to measure the pressure. Unless fundamental properties of the universe have changed, it will also be comparable to any other readings taken with mercury.
The reading process itself is a constant that you can't filter out by doing it repeatedly. Something squeezing your arm with what feels like the force of a hydraulic press surely doesn't have any weird side effects.
Anecdata, but I always get high anxiety from not being sure if the thing is actually still working properly or if it's just gonna keep pumping itself up until it explodes in my face or something. Not exactly rational but these sort of things never are. Looney toons ass machine.
"Something squeezing your arm with what feels like the force of a hydraulic press"
It shouldn't feel that crushing. I know it's common, but it shouldn't be. It's lazy/rushed healthcare professionals who only want to take it one time suing an automated machine and crank it to 200mm. If you actually put it at 140mm or take it with a manual sphig, it would read a "normal" person just fine without the crushing. The problem is, the people who are high around 130-140 need the machine at least 20mm higher and would need a retake, which means more time.
I have an automatic at-home blood pressure device, and it does the same thing. Not 200 mmHg, but high enough that I’d freak out if I didn’t know it was normal and would let up soon enough[1]. Did the product designers do that intentionally while still meeting a spec of “not panicking the user in a way that would elevate blood pressure” and getting approved for sale to non-professionals?
It seems like this is genuinely hard to work around in practice.
[1] I recall it being a staple of 80/90s tv, at least Beavis and Butthead, to have a character use an auto blood pressure device and freak out at being so clamped.
One alternative is a cuff that measures on the upswing, rather than the downswing. It does not tend to squeeze quite as hard, because it stops as soon as it has the systolic reading.
Nah. Modern automatic cuffs are adaptive. They tend to first run up pretty low (like 150), see if there is signal. If not then they have to inflate more and more. They tend to determine where to start next time based on the last reading, so if it had the go up to 200 for the last reading it’ll start there next time. If the cuff is a vise, excluding operator error the most likely cause is actually having high blood pressure.
This is why it is better to take three measurements and do an average every time to minimize errors.
The studies on correlation probably have a large enough sample size to become statistically significant - i.e. you have to read the "Method" section to find out how reliable it is, this requires certain kind of statistics and/or scientific background.
I found that that the measured BP was consistently significantly lower if I didn't look at the device's display while it was doing it's thing. This at home, with a quality device, after doing it many many times.
Also doctors and nurses are known to do an abject awful job of measuring bp according to the defined procedure. It’s usually way off when taken clinically.
Ars article here but there’s plenty in pubmed too.
> You must not eat, drink, exercise, or smoke within 30 minutes of a reading. You must have an empty bladder. You must sit straight up in a chair with back support. Your legs must be uncrossed and your feet must be flat on the ground. The arm to be measured must be rested on a flat surface so that it is at the same level as your heart, not lower, not higher. You must sit calmly, without talking for five minutes to relax before the reading. When it's time, an appropriately sized cuff should be wrapped around your bare upper arm, right above the elbow; it should never be wrapped over clothing. At least two readings should be taken, with the average recorded. Ideally, readings should be taken in both arms, with the highest readings recorded.
When was the last time you got it measured properly? Literally never for me in a clinical setting. I don’t know why they bother honestly.
Probably never, I have really long arms and they usually take it just barely above the elbow also. I have always been on the higher end even when in my 20s and training/dieting for athletic events.
Used to flummox me until I bought my own meter, they can be like $30.
Reading around (e.g. [0]) it sounds like variance isn't something researchers care for, probably with the assumption that screening with a higher value is better than missing an issue from a lower value.
We see the same for body temperature (speed and convenience is usually prioritized over accuracy) and weight (2% variation is largely accepted). Afterall guidelines are already off as by definition, as they don't account for individual circumstances, so perhaps aiming for accuracy is useless in most settings.
As long as blood pressure variance is randomized then you’re getting a signal, and that happens when everyone is measured in a similar way (or randomized to different ways). You don’t need perfect precision.
What you don’t want is to make everyone who, say, smokes wear the cuff while standing up while everyone else gets cuffed lying down.
> and that happens when everyone is measured in a similar way (or randomized to different ways)
But that's exactly the issue -- that the similarity or randomness is one way for one study, and another way for another study, because of culturally different sets of nurses and/or patients.
In other words, you're right it's not affecting results within a study, but it makes comparison between studies questionable.
And it makes it equally questionable whether a study's results apply to you, if your signal is 10 units off of a study's signal, and occurs across a cutoff that determines whether you should take a medication or not.
I guess it depends on the study. If it is just comparing between groups, the conclusions probably still hold if they consistently measured blood pressure in the "incorrect" way. If it is something like "85% of Americans have high blood pressure", then probably the conclusions are incorrect because they are comparing the "correct" baseline against an incorrect measurement method. There are also other ways to measure blood pressure, like recent smartwatches - so read the methods section carefully, I guess.
Exactly, this is my concern as well. They say you have to be seated for 5 minutes at least, completely relaxed, not hungry, not having to go the bathroom, in a quiet a room, it must not be too hot or too cold, with both your feet on the ground, before you can have your blood pressure measured, otherwise the reading could be 'artificially' high. Really? It seems to me that if you do all these preparations, the reading will be artificially low, since such conditions are nothing like the conditions that you'll typically find yourself in through the day in your everyday life.
The goal is to get a clinically relevant measurement, captured at rest under specific conditions, not a measurement that's representative of a random moment during everyday life.
My wife had a Cryo Chamber Therapy for a few weeks and had to measure pressure and pulse before each session so they let her in. After about a week she was refused entry because her pressure was too high (when she measured it at home - it was normal).
Since then she had problems getting admited every time, and she started to fear the measurement (she had to drive there during work and do overtime later).
She started arguing with the guy and wasted like 5 days driving there and back during work without having another session because the pressure and pulse were too high (despite both being OK at home).
Eventually she went to another person in that hospital to measure her pressure. It was perfect. But when the guy near the entrance to the cryo chamber measured it - it was too high to let her enter.
They tried different instruments and the difference was the same. When the guy measured it - it was too high. When somebody else measured it - it was fine. Finally they let her do the cryo chamber without the guy permission :)
We assumed the difference was just that she was anxious and frustrated when she's seen the guy, but now I wonder if the difference was the position in which he measured the pressure.
Had the exact same thing happen when I was doing a Ketamine therapy thing a while back, and I definitely think the anxiousness about the reading had something to do with it.
I've always had perfectly okay blood pressure whenever I have it done at a regular doctor's appointment, so I think knowing that the reading actually matters definitely increases my blood pressure. Ended up getting a doctor's note saying "they don't actually have high blood pressure they are just reacting normally to possibly having to be sent home and reschedule" more or less.
When my heart went to hell, I bought a blood pressure monitor. Before I left the hospital, I had to agree to religiously test my blood pressure three times a day at the exact same time. Anything beyond that was a bonus, but to provide useful data I needed those three readings a day.
As my cardiologist explained, 39 year olds don’t randomly end up spending a week in a cardiac ward so he needed better data to form a holistic treatment plan.
I'm one of them. I bought a device with memory and covered the screen with a piece of card. Then I take BP for two weeks and ignore the first few days' readings. I seem to get used to it after a few days. This gets me readings that are very close to 120/80.
I've had anxiety about blood pressure ever since running for an appointment, while being on the first day of a new job when I was really amped up, and so (of course) had a dangerously high reading. I still remember the guy's eyes widening as he looked at the screen. Ever since then I've hated having BP taken and I can feel my BP and pulse increasing the moment I step into a doctor's office. Fortunately my doctor understands and doesn't try to push pills on me.
I wish there were some way of measuring BP without knowing it's being done. The act of measurement can greatly affect the result, which is counter-productive in several ways (not the least of which is un-needed anxiety).
York Cardiologist on Youtube is good on BP, and why apparently high BP should not automatically mean pills, although undoubtedly it sometimes should. (Usual disclaimer: this is not medical advice, ask your doctor about your specific situation.)
I remember when I was a kid, the doctor thought that my blood pressure was too high. Of course, I was just anxious because I knew they were going to give me a shot. What kid wouldn't be?? He took it again after I got the shot and it went back down to normal.
I've never looked into research on this subject, but I always assumed this was already well established and known - and it was definitely somewhat already either known or at least believed to be the case:
- Every doctor in the UK I've ever seen do a BP test has made sure the patient's arm is in the right position, rested on a table/cushion if needed, in a way that matches the findings in this study (and while I've only needed my own BP tested once or twice, I've sat in on many, many doctors while they tested the BP of family members of mine).
- My home BP device is a Braun wrist cuff (and is at least a few years old), which has a built in feature that uses an accelerometer to guide you to raise your arm until it's at an angle which means your wrist is at the same level as your heart (this one: https://www.cora.health/guide/best-blood-pressure-monitor/#1... )
Yes - it's just a digital spirit level of sorts, that instead of being calibrated to align with the ground is calibrated such that, based on typical angles and dimensions of a human body leads to the wearer holding their arm up in front of them with the device in line with the heart.
Here's what it looks like, the device won't start until you've got the ball to hover in the middle circle, but it has no way of knowing if you're doing it properly or if you're lying down or leaning your body forwards or whatever else would mean that the angles no longer put it level with your heart.
Basically the same logic as, for traditional upper arm cuff devices, giving the instruction to rest your arm on something next to you that allows your forearm to be resting both comfortably and straight, parallel to the floor - which again, doesn't technically mean the middle of your upper arm must be level with your heart, but since nobody would really be comfortable putting their forearm flat on a low down coffee table or a high up standing desk it works as a proxy that's simpler than asking people to think about lining anything up with their internal organs.
I am not a doctor and this is not advice. This is a standard medical test I have completely given up on any doctor to perform accurately. I do it myself at home once or twice a month. I do it with the same device, in the same chair, at the same desk, the same time of day, after I’ve ate and drank the same thing. Yes, I still let everyone take it because it’s typically a precondition of receiving care but my readings at home are completely different and give me a more accurate data point that actually makes me feel good about the progress I’ve been making on my health.
I’m actively looking for more healthcare I can do this way. I trust my data and it all coming together on the safety of my personal device. We don’t need doctors with extremely limited datasets to do this and try to find obscure correlations for us.
>This is a standard medical test I have completely given up on any doctor to perform accurately. I do it myself at home once or twice a month. I do it with the same device, in the same chair, at the same desk, the same time of day, after I’ve ate and drank the same thing.
You are assuming the average patient is this careful about measuring their BP, or anything about their health. You are also assuming the average patient measures their BP correctly, which is obviously untrue as evidenced by some other comments on this post. You are also assuming patients always tell the truth about their own measurements.
>We don’t need doctors with extremely limited datasets to do this and try to find obscure correlations for us.
I don't understand what you mean by this. None of us finds obscure correlations with limited datasets. We don't diagnose someone over a single BP measurement.
> We don't diagnose someone over a single BP measurement.
Yeah I feel like no doctor of mine has ever been the type to do that. My current PCP wouldn't prescribe meds for hypertension until after I took my own BP at home for a month (it was not catastrophically high when measured at his office, he might have taken a different approach in that situation).
Even with a catastrophically high measurement, no doctor would diagnose with a single data point. At worst, they would ask the patient to measure at home multiple times a day, after teaching the correct method of measurement. At best, they would do an ambulatory monitoring.
My doctor recommended doing it first thing in the morning, before eating or drinking anything. That's probably an easier way for the general population to establish a consistent baseline
I've achieved exciting results by flatly refusing vitals checks at each and every medical appointment. Especially psychiatrists. The PCPs always gamely admire my self-reported histories and graphs, commenting how nicely the trend line goes down, and then completely dismiss the results in their clinical notes.
However, I did lock horns with a particular chiropractor. I filled out the "pre-existing conditions" form with candor and honesty. I permitted a BP check. (His method was 100% manual sphygmomanometer.)
Then he informed me that he wouldn't touch me until my BP was controlled and normal. Yes, a chiropractor, not a cardiac surgeon. Geez.
In the past, I've tried to avoid submitting to blood draws and labs, because those are 100% fishing expeditions, and not actually attempting to diagnose a complaint or symptoms. (They love to misdiagnose hypothyroid or diabetes so they can begin destroying your endocrines.)
Unfortunately, clinics do these orders on a schedule, so if you avoid labs for a while, the orders simply pile up until they contrive to get them all done. I couldn't win. Still putting off colonoscopy: 2.5 years late, and counting!
Every single health related thread is like this. Dude thinks because he's been programming JavaScript for 10 years he's a literal genius. It's pathetic.
But why go to these practitioners if you don't trust them ? Nobody should be forcing you. Is it because you want access to treatment solely on your own terms ?
Blood pressure measurements at the doctor are the bane of my (medical) existence. Mix minor white coat syndrome with time blindness and you suddenly have high blood pressure because you barreled up the stairs to the second floor office moments before the nurse took a reading.
My doctor was initially befuddled because by all other metrics I am in good health, but it’s amazing how you can go from 90/55 at home to 140/75 at the office. We do the measurement at the end of the appointment now to varying success.
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.
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 :)
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".
Weird, I ride my bike to the doctor, my heart rate is often elevated from the ride and my blood pressure is still normal (barely above low - though I've had enough different tests over the years to believe that exercise is having nearly zero effect)
Lie down on a bed on your back, and put the cuff on your arm and get the 'button' within reach of your finger to turn it on. Then completely relax (and DO NOT move) with soft music or whatever. Then without moving your body at all, after 10 minutes (at least) push the button to start the pressurization and reading.
This gives an accurate reading and is often DRAMATICALLY lower than if you don't do it this way. I was convinced I had super high potentially life-threatening BP until I learned this.
Now if you want to see I'm right, get up and walk around some and then sit back down and take another reading. It will be noticeably higher, because your heart starts pumping harder even from minimal movement.
>This gives an accurate reading and is often DRAMATICALLY lower
Just because it gives lower results doesn't mean it's more accurate. I can raise my arm during measurement or use a tourniquet above the cuff and get a lower result. That doesn't mean the measurement is accurate at all.
There are standardized procedures on how to measure BP. Your "accurate" method is not one of them.
I don't disagree, but wouldn't the counterargument be that the 120/80 and 140/90 thresholds (or whatever they've redefined hypertension as) apply precisely to sitting rather than lying, and after only a minute's stillness, rather than ten? And also that you spend 16 hours out of 24 not lying down?
You don’t live your day to day life listening to soft music, lying down ready to doze. If your BP is elevated due to stress throughout the day it’s elevated, you will accumulate the harms. Idealizing conditions also gives a misleading reading.
> Now if you want to see I'm right, get up and walk around some and then sit back down and take another reading.
This doesn’t prove you’re right, just demonstrates normal physiology. Kind of like saying when you dyno an engine you should do it at idle. That is a valid measurement, just not the one that’s interesting.
In a healthy adult you will see a more significant increase in systolic pressure, but mean pressure shouldn’t rise nearly as greatly.
What you’re trying to observe is not the minimum ideal (your method) nor the short term maximums but an average of normal activity.
There’s a reason why ambulatory BP monitoring is the gold standard for diagnosing hypertension.
I've heard that for some people it's exactly the opposite. Standard procedure, IIRC, is to have the arm resting in a position that puts the cuff right about even with your heart. But some people get really big jumps in BP when supine, and I've heard it suggested that doctors might want to start doing their BP tests in that position because those people may not get diagnosed correctly despite spending a third of every day with high blood pressure.
I've never seen a nurse not insist on the right position.
However I've always wondered how much of a difference my long torso makes when my blood pressure is measured. I'm 6'3", and it's mostly torso. The result is that a table that is the right height for most people, is low for me. And adjusting the table to match my body is something that I've seen a lot of variation on.
Seems it would be easy to equip exam rooms with a set of basic foam blocks that could help with patient positioning for this and other routine procedures.
Can any medical professionals chime in on how it's usually done for tall folks?
"Long torso body type" is, in general, an under-appreciated factor in ergonomics and product design, IMO.
A couple of off-the-cuff examples:
-The longer your torso, the worse a laptop computer affects your neck and posture. For long folks, upright posture requires keyboard and monitor to be vertically separated even more than most off-the-shelf monitor/desk/keyboard trays will allow. So a monitor hinged directly to a keyboard is the worst of all possible configurations.
-Most recent automotive seats seem to force the head forward, excessively curving the spine, and the longer the torso the worse the effect.
On the opposite side of the bell curve, a safe driving position is hard to achieve for drivers around 5ft tall and under. Correct/safe distance from airbags and pedals seems to be overlooked for those of shorter stature.
I wish solving problems experienced by body proportion outliers was a higher priority for product companies.
Why are recent auto head rests doing this? I hate it and I am nearly to the point of removing the head rest when I drive (but maybe that has downsides in an accident scenario).
Add clothes to that list. It's such a pain in the butt to find shirts made for people who are long torso without ending up with a shirt that's larger in every other dimension too. Even ones specifically labeled 'tall'
You need to find brands that have a slim sizing variation, coupled with a tall sizing variation. Ex j crew pre private equity, had good slim tall offerings.
I am a skeptic about the diagnostic criteria for hypertension, and especially about low targets for management. Cochrane did a meta review not long ago that made it sound like the signal was pretty weak below about 160/100 (as you might expect, if the measurement wasn't very accurate, which I don't think it is). I'm not saying it's not dangerous at much higher levels, but if you're freaking out at 140/90 because a chart says STAGE TWO, imo you can take a chill pill.
As a just-in-time bordering on chronically late individual (typical engineer), sprinting on foot or bicycle to the doctor’s office has led to some unusually high reading.
Putting aside the implementation technicalities, which I know nothing about, I'm convinced that markedly superior outcomes will be driven by something (e.g. watch-like devices) that captures entire weeks worth of regular BP readings across all times of day and night to provide a significant body of data.
I was also fed up with inaccurate readings, and was trying to prototype a medical device that would have an adjustable cuff based on arm size. I ran it by my concierge doc, but apparently the latest tech is to use light waves to measure BP, similar to how wearables are doing pulse OX and Heart Rate. The technique is known as Photoplethysmography (PPG).
Only time I ever recall a nurse that insisted on doing BP measurements wrong was .. in jail. And not like all the nurses there, just this one person who did not care about anything besides flirting with corrections officers and getting the hell out of there ASAP.
> "If you are consistently measuring blood pressure with an unsupported arm, and that gives you an overestimated BP of 6.5 mmHg, that's a potential difference between a systolic BP of 123 and 130, or 133 and 140—which is considered stage 2 hypertension,"
Okay, but that's a small and borderline difference?
If you're +-7 in your reading, don't panic yet. If you're there with a stage 1 or 2 hypertension diagnosis (130-140+ systolic), the margin of error discussed in this article isn't necessarily meaningless, but remarkably close to it - you need to address an issue there.
More as a PSA for you hardworking programmers and IT managers out there: if you have chronic hypertension, address it sooner than later. If you think to yourself that you'll start jogging daily starting next week, and your doctor is giving you the option for meds, just get on the damn meds. If you start an exercise regimen that can quantifiably manage it without the meds later, great. Don't let the perfect be the enemy of the good. Hypertension is the silent killer, and before it kills it contributes to all sorts of other bad problems and conditions.
Yeah, I empathize. Glad you're doing better now, assuming you are. I would get awful headaches and nausea (like hide in a dark room, photophobic, overly sensitive to sound, smells, wishing I could chop my head off). For years I didn't connect the two. Felt like getting the worst two-day hangover without having drank anything, but if I had measured my blood pressure at the time it would have been well over 150. I clocked in at 170 during one of those episodes when I went to urgent care. For years I had just dismissed as having overdid it the prior week and just needed to rest. Even if you can put up with the pain like a badass, it's not healthy for your system to be redlining so often. It does its damage in the aggregate.
Wearing a waffle pattern shirt can also make the reading high. My blood pressure is 20 points higher if I wear a waffle pattern shirt than if I take it off.
That sounds like the guy who thought he had a leather allergy because whenever he woke up with his shoes still on he had a terrible headache and felt nauseous.
every time I get my blood pressure measured, my arm hangs on some scaffolding thing the blood pressure cuff hangs from. not even an armrest. Height is also not really standard.
that said, arm was not in my lap, and not hanging freely at my side.
I’ve never seen a discussion how ‘reactive’ one is physiologically either when discussing BP. That is, is one the kind of person who is generally calm throughout the day, or is one who has larger swings based on various stimuli? I’ve had readings as high as 155/95 when stressed rushing to a doctor’s office visit and readings as low as 105/62 when calmer. I suspect blood pressures varies wildly through the day, and this variation depends on a person’s physiology.
>I’ve never seen a discussion how ‘reactive’ one is physiologically
Then you have never looked for it. This is pretty basic stuff taught in the very first year of the medical school.
>when stressed rushing to a doctor’s office visit
Even has a name: white coat hypertension.
>I suspect blood pressures varies wildly through the day, and this variation depends on a person’s physiology.
Yes it absolutely does. Just like your heart rate varies throughout the day, your BP keeps changing as well. That's why we like to measure it over 24 hours before any diagnosis.
I had a major heart scare when I was 39 so I’m quite obsessed with my blood pressure. This is anecdata based off of my own experience with my heart, brain and body.
(Note that this is based off of someone capable of developing a heart problem in his late thirties so hopefully none of this will apply.)
Before I started running for fun, running up to a doctor’s office would absolutely spike my blood pressure. That was a combination of anxiety (which is/was an issue), cardiovascular health and basic physical reactions to exertion. Since I started running for fun, that relationship has completely changed. I don’t get the anxiety based blood pressure changes because I find running really fun and rewarding.
When I lift weights, my blood pressure will read a little higher for at least 24 hours after. The heavier I lift, the more my blood pressure will lift. I see a similar relationship with volume, but it’s not as linear as weight. So if I have to do fifty total reps to failure my blood pressure will be higher, but not as high as if I had done ten total reps to failure.
Food and alcohol have tremendous impacts. Cannabis has an impact but nowhere near the impact of either food or alcohol. Armed only with blood pressure data, I could make a good case for fast food and beer to be illegal. My case wouldn’t be as strong for cannabis. Caffeine is really fucking weird - it increases blood pressure up to the point of addiction. Then, not feeding the addiction will spike my blood pressure even more.
And I haven’t even begun to talk about how heavily my brain is involved. I dealt with undiagnosed ADHD through developing some very obsessive habits. As a consequence, I can quite literally obsess my way back to blood pressure medication.
Judging by how much personal data I have on my blood pressure, I’m sure you’re very surprised that I tend to be obsessive. :)
So anecdotally, you are 100% correct. But I can add some more anecdotes to hopefully ease your mind. When I got out of the hospital, I had to promise my cardiologist three perfect readings a day; meaning that I would religiously check my blood pressure at the same three times each day. Needless to say, I checked it way more than that. But there is an awareness that different levels of need require different levels of scrutiny.
The only part I still wonder is if my cardiologist knew that giving an obsessive person metrics would lead me into running. This may have just been a way to get me back into shape.
I had a similar issue, which was remedied by getting a larger cuff. In retrospect it makes sense that one size does not fit all, and apparently my biceps are on the larger side.
Cuff sizes are targeted to a range of arm sizes. The range should be stated either on the cuff or in the manual. Using improper sizes over/underestimates the pressure values.
Real-life medical practice is basically going through the motions, then intuitively guessing the issue, prescribing something common since most cases are so banal and next patient please.
Engineer-minded people can discover lots and lots of such "obvious" issues in healthcare and of course the answer isn't that nobody would've guessed it, it just doesn't matter. Healthcare (outside of very specific diagnosable illnesses) is 90%+ medicine theater. People expect some pills, they want a few words with someone in a white coat, and their problem goes away usually by itself. Chronic persistent issues without obvious cause befuddle docs and they often don't find anything even after lots of tests.
Our better health and longevity today is more due to better work conditions, better food, better sanitation and food preservation, basic vaccines, basic disinfectants, basics like penicillin, smoking less etc. And the low hanging fruit to improve further is lifestyle: eating/drinking fewer calories (especially less sugary stuff), exercising/sleeping more and having better social connections. None of it is particularly arcane or in need of precise measurement.
> Engineer-minded people can discover lots and lots of such "obvious" issues in healthcare
It is a defining characteristic of "engineer-minded people" to think they understand better than others. Amusingly, they won't pretend to repair their car engine better than a mechanic, but they will strongly believe they understand all the bad tricks and failings of doctors. They almost never understand that current medicine is mostly experience and not hard science. Future medicine is science. 2024 medicine is not, and cannot be.
Honestly I'm not sure what a single point-in-time reading even accomplishes. I've been hooked up to a continuous blood pressure monitor a few times and it's always fun to see how low I can get it. It seems pretty useless without seeing where it fluctuates over time not in a doctor's office.
Once, when hospitalized, I had an arterial BP monitor that was continuous. The last systolic number I remember seeing before passing out from sepsis was in the 70s.
Yet another medical topic being discussed on HN, with comments full of disinformation and skeptics that think they've noticed something new that doctors have missed. Remember people, don't take medical advice from HN.
Well, it's clearly an echo chamber. There's very little actual transmission of knowledge in those topics. It's almost always about confirming pre existing beliefs.
I'm an MD too, but I've been raised by scientists. Scientists in my own family entertain the same beliefs exhibited by HNers, to surprising extremes such as dismissing the effect of even very well understood drugs.
Last year, my father stopped his blood pressure meds and was very surprised when I could guess he'd stopped just by looking at him, then proceeded to explain how the drugs acted, and got even more surprised when he got much better 15 min after taking them again. Since then, he totally forgot about this event and is in complete denial.
You can't change beliefs by explanation. People have to get to their own conclusions, otherwise you're just fighting windmills all the time.
Nice to see a fellow MD (very possibly older and more experienced than me) on HN.
>he totally forgot about this event and is in complete denial.
I can never understand this, especially with well educated people like your father or mine. I can't get mine to agree to go see a doctor (other than me - he doesn't believe me when I tell him something about medicine) for anything, even when there are obvious problems with his health.
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.?
> Is the blood pressure really being measured "correctly" in all those studies? Or not?
This is why you do readings three different times a day for several days. And why there’s instructions on how long to dust still before the readings, why you do three repeats with multiple minutes of wait in between, and finally why the averages of those readings aren’t just simple averages. But yes you always have to wonder about every study using self reported home readings if they follow the instructions or not, because it is tedious to do it correctly.
> This is why you do readings three different times a day for several days.
What good is this if my monitor is not as accurate as the one at a doctor's office? It's not like my doctor would take my monitor's readings over his.
You might be surprised. "White coat hypertension" is well-known. Someone with a reliable set of readings from home would be more convincing than someone who says "I get it read at Walmart/CVS once a month and it's ok".
Your doctor's office's monitor isn't incredibly accurate. If you want accurate, you need a mercury sphygmomanometer to measure the pressure. Unless fundamental properties of the universe have changed, it will also be comparable to any other readings taken with mercury.
The reading process itself is a constant that you can't filter out by doing it repeatedly. Something squeezing your arm with what feels like the force of a hydraulic press surely doesn't have any weird side effects.
Anecdata, but I always get high anxiety from not being sure if the thing is actually still working properly or if it's just gonna keep pumping itself up until it explodes in my face or something. Not exactly rational but these sort of things never are. Looney toons ass machine.
"Something squeezing your arm with what feels like the force of a hydraulic press"
It shouldn't feel that crushing. I know it's common, but it shouldn't be. It's lazy/rushed healthcare professionals who only want to take it one time suing an automated machine and crank it to 200mm. If you actually put it at 140mm or take it with a manual sphig, it would read a "normal" person just fine without the crushing. The problem is, the people who are high around 130-140 need the machine at least 20mm higher and would need a retake, which means more time.
I have an automatic at-home blood pressure device, and it does the same thing. Not 200 mmHg, but high enough that I’d freak out if I didn’t know it was normal and would let up soon enough[1]. Did the product designers do that intentionally while still meeting a spec of “not panicking the user in a way that would elevate blood pressure” and getting approved for sale to non-professionals?
It seems like this is genuinely hard to work around in practice.
[1] I recall it being a staple of 80/90s tv, at least Beavis and Butthead, to have a character use an auto blood pressure device and freak out at being so clamped.
One alternative is a cuff that measures on the upswing, rather than the downswing. It does not tend to squeeze quite as hard, because it stops as soon as it has the systolic reading.
e.g. Omron BP7000
There might be a repeatability thing. Always give the full pressure then at least it's one less variable to account for.
Nah. Modern automatic cuffs are adaptive. They tend to first run up pretty low (like 150), see if there is signal. If not then they have to inflate more and more. They tend to determine where to start next time based on the last reading, so if it had the go up to 200 for the last reading it’ll start there next time. If the cuff is a vise, excluding operator error the most likely cause is actually having high blood pressure.
Just to point, it's known that a sizeable segment of the population reacts to the pressure measuring process with increased blood pressure.
This is why it is better to take three measurements and do an average every time to minimize errors.
The studies on correlation probably have a large enough sample size to become statistically significant - i.e. you have to read the "Method" section to find out how reliable it is, this requires certain kind of statistics and/or scientific background.
I found that that the measured BP was consistently significantly lower if I didn't look at the device's display while it was doing it's thing. This at home, with a quality device, after doing it many many times.
Yes, i experiment with eyes open/closed as well
Also doctors and nurses are known to do an abject awful job of measuring bp according to the defined procedure. It’s usually way off when taken clinically.
Ars article here but there’s plenty in pubmed too.
https://arstechnica.com/health/2024/10/your-doctors-office-c...
[edit] The prep guidance is…
> You must not eat, drink, exercise, or smoke within 30 minutes of a reading. You must have an empty bladder. You must sit straight up in a chair with back support. Your legs must be uncrossed and your feet must be flat on the ground. The arm to be measured must be rested on a flat surface so that it is at the same level as your heart, not lower, not higher. You must sit calmly, without talking for five minutes to relax before the reading. When it's time, an appropriately sized cuff should be wrapped around your bare upper arm, right above the elbow; it should never be wrapped over clothing. At least two readings should be taken, with the average recorded. Ideally, readings should be taken in both arms, with the highest readings recorded.
When was the last time you got it measured properly? Literally never for me in a clinical setting. I don’t know why they bother honestly.
Probably never, I have really long arms and they usually take it just barely above the elbow also. I have always been on the higher end even when in my 20s and training/dieting for athletic events.
Used to flummox me until I bought my own meter, they can be like $30.
Reading around (e.g. [0]) it sounds like variance isn't something researchers care for, probably with the assumption that screening with a higher value is better than missing an issue from a lower value.
We see the same for body temperature (speed and convenience is usually prioritized over accuracy) and weight (2% variation is largely accepted). Afterall guidelines are already off as by definition, as they don't account for individual circumstances, so perhaps aiming for accuracy is useless in most settings.
[0] https://www.mayoclinic.org/diseases-conditions/high-blood-pr...
As long as blood pressure variance is randomized then you’re getting a signal, and that happens when everyone is measured in a similar way (or randomized to different ways). You don’t need perfect precision.
What you don’t want is to make everyone who, say, smokes wear the cuff while standing up while everyone else gets cuffed lying down.
> and that happens when everyone is measured in a similar way (or randomized to different ways)
But that's exactly the issue -- that the similarity or randomness is one way for one study, and another way for another study, because of culturally different sets of nurses and/or patients.
In other words, you're right it's not affecting results within a study, but it makes comparison between studies questionable.
And it makes it equally questionable whether a study's results apply to you, if your signal is 10 units off of a study's signal, and occurs across a cutoff that determines whether you should take a medication or not.
I guess it depends on the study. If it is just comparing between groups, the conclusions probably still hold if they consistently measured blood pressure in the "incorrect" way. If it is something like "85% of Americans have high blood pressure", then probably the conclusions are incorrect because they are comparing the "correct" baseline against an incorrect measurement method. There are also other ways to measure blood pressure, like recent smartwatches - so read the methods section carefully, I guess.
My doctor was handing me, hypertension, pamphlets, and talking about medication.
Finally realized, that I was habitually late, getting to my appointments and always taking the stairs.
Don’t do that.
Exactly, this is my concern as well. They say you have to be seated for 5 minutes at least, completely relaxed, not hungry, not having to go the bathroom, in a quiet a room, it must not be too hot or too cold, with both your feet on the ground, before you can have your blood pressure measured, otherwise the reading could be 'artificially' high. Really? It seems to me that if you do all these preparations, the reading will be artificially low, since such conditions are nothing like the conditions that you'll typically find yourself in through the day in your everyday life.
The goal is to get a clinically relevant measurement, captured at rest under specific conditions, not a measurement that's representative of a random moment during everyday life.
My wife had a Cryo Chamber Therapy for a few weeks and had to measure pressure and pulse before each session so they let her in. After about a week she was refused entry because her pressure was too high (when she measured it at home - it was normal).
Since then she had problems getting admited every time, and she started to fear the measurement (she had to drive there during work and do overtime later).
She started arguing with the guy and wasted like 5 days driving there and back during work without having another session because the pressure and pulse were too high (despite both being OK at home).
Eventually she went to another person in that hospital to measure her pressure. It was perfect. But when the guy near the entrance to the cryo chamber measured it - it was too high to let her enter.
They tried different instruments and the difference was the same. When the guy measured it - it was too high. When somebody else measured it - it was fine. Finally they let her do the cryo chamber without the guy permission :)
We assumed the difference was just that she was anxious and frustrated when she's seen the guy, but now I wonder if the difference was the position in which he measured the pressure.
Had the exact same thing happen when I was doing a Ketamine therapy thing a while back, and I definitely think the anxiousness about the reading had something to do with it.
I've always had perfectly okay blood pressure whenever I have it done at a regular doctor's appointment, so I think knowing that the reading actually matters definitely increases my blood pressure. Ended up getting a doctor's note saying "they don't actually have high blood pressure they are just reacting normally to possibly having to be sent home and reschedule" more or less.
When my heart went to hell, I bought a blood pressure monitor. Before I left the hospital, I had to agree to religiously test my blood pressure three times a day at the exact same time. Anything beyond that was a bonus, but to provide useful data I needed those three readings a day.
As my cardiologist explained, 39 year olds don’t randomly end up spending a week in a cardiac ward so he needed better data to form a holistic treatment plan.
Quite a few people here report getting anxious even when taking their BP themselves:
https://www.innerhealthstudio.com/phobia-taking-blood-pressu...
I'm one of them. I bought a device with memory and covered the screen with a piece of card. Then I take BP for two weeks and ignore the first few days' readings. I seem to get used to it after a few days. This gets me readings that are very close to 120/80.
I've had anxiety about blood pressure ever since running for an appointment, while being on the first day of a new job when I was really amped up, and so (of course) had a dangerously high reading. I still remember the guy's eyes widening as he looked at the screen. Ever since then I've hated having BP taken and I can feel my BP and pulse increasing the moment I step into a doctor's office. Fortunately my doctor understands and doesn't try to push pills on me.
I wish there were some way of measuring BP without knowing it's being done. The act of measurement can greatly affect the result, which is counter-productive in several ways (not the least of which is un-needed anxiety).
York Cardiologist on Youtube is good on BP, and why apparently high BP should not automatically mean pills, although undoubtedly it sometimes should. (Usual disclaimer: this is not medical advice, ask your doctor about your specific situation.)
I remember when I was a kid, the doctor thought that my blood pressure was too high. Of course, I was just anxious because I knew they were going to give me a shot. What kid wouldn't be?? He took it again after I got the shot and it went back down to normal.
I've never looked into research on this subject, but I always assumed this was already well established and known - and it was definitely somewhat already either known or at least believed to be the case:
- Every doctor in the UK I've ever seen do a BP test has made sure the patient's arm is in the right position, rested on a table/cushion if needed, in a way that matches the findings in this study (and while I've only needed my own BP tested once or twice, I've sat in on many, many doctors while they tested the BP of family members of mine).
- My home BP device is a Braun wrist cuff (and is at least a few years old), which has a built in feature that uses an accelerometer to guide you to raise your arm until it's at an angle which means your wrist is at the same level as your heart (this one: https://www.cora.health/guide/best-blood-pressure-monitor/#1... )
Can you trick the Braun device into thinking your wrist is level with you heart?
Yes - it's just a digital spirit level of sorts, that instead of being calibrated to align with the ground is calibrated such that, based on typical angles and dimensions of a human body leads to the wearer holding their arm up in front of them with the device in line with the heart.
Here's what it looks like, the device won't start until you've got the ball to hover in the middle circle, but it has no way of knowing if you're doing it properly or if you're lying down or leaning your body forwards or whatever else would mean that the angles no longer put it level with your heart.
https://imgur.com/a/pV6xcpc
edit to add: so when used correctly it looks roughly like this - https://m.media-amazon.com/images/S/aplus-media/vc/573a171a-...
Basically the same logic as, for traditional upper arm cuff devices, giving the instruction to rest your arm on something next to you that allows your forearm to be resting both comfortably and straight, parallel to the floor - which again, doesn't technically mean the middle of your upper arm must be level with your heart, but since nobody would really be comfortable putting their forearm flat on a low down coffee table or a high up standing desk it works as a proxy that's simpler than asking people to think about lining anything up with their internal organs.
I am not a doctor and this is not advice. This is a standard medical test I have completely given up on any doctor to perform accurately. I do it myself at home once or twice a month. I do it with the same device, in the same chair, at the same desk, the same time of day, after I’ve ate and drank the same thing. Yes, I still let everyone take it because it’s typically a precondition of receiving care but my readings at home are completely different and give me a more accurate data point that actually makes me feel good about the progress I’ve been making on my health.
I’m actively looking for more healthcare I can do this way. I trust my data and it all coming together on the safety of my personal device. We don’t need doctors with extremely limited datasets to do this and try to find obscure correlations for us.
>This is a standard medical test I have completely given up on any doctor to perform accurately. I do it myself at home once or twice a month. I do it with the same device, in the same chair, at the same desk, the same time of day, after I’ve ate and drank the same thing.
You are assuming the average patient is this careful about measuring their BP, or anything about their health. You are also assuming the average patient measures their BP correctly, which is obviously untrue as evidenced by some other comments on this post. You are also assuming patients always tell the truth about their own measurements.
>We don’t need doctors with extremely limited datasets to do this and try to find obscure correlations for us.
I don't understand what you mean by this. None of us finds obscure correlations with limited datasets. We don't diagnose someone over a single BP measurement.
> We don't diagnose someone over a single BP measurement.
Yeah I feel like no doctor of mine has ever been the type to do that. My current PCP wouldn't prescribe meds for hypertension until after I took my own BP at home for a month (it was not catastrophically high when measured at his office, he might have taken a different approach in that situation).
Even with a catastrophically high measurement, no doctor would diagnose with a single data point. At worst, they would ask the patient to measure at home multiple times a day, after teaching the correct method of measurement. At best, they would do an ambulatory monitoring.
> after I’ve ate and drank the same thing
My doctor recommended doing it first thing in the morning, before eating or drinking anything. That's probably an easier way for the general population to establish a consistent baseline
It's not only easier, but the actual correct way of doing it. That's why your doctor recommended it.
> typically a precondition of receiving care
I've achieved exciting results by flatly refusing vitals checks at each and every medical appointment. Especially psychiatrists. The PCPs always gamely admire my self-reported histories and graphs, commenting how nicely the trend line goes down, and then completely dismiss the results in their clinical notes.
However, I did lock horns with a particular chiropractor. I filled out the "pre-existing conditions" form with candor and honesty. I permitted a BP check. (His method was 100% manual sphygmomanometer.)
Then he informed me that he wouldn't touch me until my BP was controlled and normal. Yes, a chiropractor, not a cardiac surgeon. Geez.
In the past, I've tried to avoid submitting to blood draws and labs, because those are 100% fishing expeditions, and not actually attempting to diagnose a complaint or symptoms. (They love to misdiagnose hypothyroid or diabetes so they can begin destroying your endocrines.)
Unfortunately, clinics do these orders on a schedule, so if you avoid labs for a while, the orders simply pile up until they contrive to get them all done. I couldn't win. Still putting off colonoscopy: 2.5 years late, and counting!
>Still putting off colonoscopy
I hope you won't regret putting it off.
>They love to misdiagnose hypothyroid or diabetes so they can begin destroying your endocrines
Yes, my favorite pastime when I'm bored of treating "actual" diseases.
I fail to understand how a well-educated group of people (aka. HN) can be this against the scientific method.
Every single health related thread is like this. Dude thinks because he's been programming JavaScript for 10 years he's a literal genius. It's pathetic.
[delayed]
But why go to these practitioners if you don't trust them ? Nobody should be forcing you. Is it because you want access to treatment solely on your own terms ?
Blood pressure measurements at the doctor are the bane of my (medical) existence. Mix minor white coat syndrome with time blindness and you suddenly have high blood pressure because you barreled up the stairs to the second floor office moments before the nurse took a reading.
My doctor was initially befuddled because by all other metrics I am in good health, but it’s amazing how you can go from 90/55 at home to 140/75 at the office. We do the measurement at the end of the appointment now to varying success.
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.
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 :)
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".
Weird, I ride my bike to the doctor, my heart rate is often elevated from the ride and my blood pressure is still normal (barely above low - though I've had enough different tests over the years to believe that exercise is having nearly zero effect)
I'm convinced most people take BP wrong.
Here's how:
Lie down on a bed on your back, and put the cuff on your arm and get the 'button' within reach of your finger to turn it on. Then completely relax (and DO NOT move) with soft music or whatever. Then without moving your body at all, after 10 minutes (at least) push the button to start the pressurization and reading.
This gives an accurate reading and is often DRAMATICALLY lower than if you don't do it this way. I was convinced I had super high potentially life-threatening BP until I learned this.
Now if you want to see I'm right, get up and walk around some and then sit back down and take another reading. It will be noticeably higher, because your heart starts pumping harder even from minimal movement.
>This gives an accurate reading and is often DRAMATICALLY lower
Just because it gives lower results doesn't mean it's more accurate. I can raise my arm during measurement or use a tourniquet above the cuff and get a lower result. That doesn't mean the measurement is accurate at all.
There are standardized procedures on how to measure BP. Your "accurate" method is not one of them.
I don't disagree, but wouldn't the counterargument be that the 120/80 and 140/90 thresholds (or whatever they've redefined hypertension as) apply precisely to sitting rather than lying, and after only a minute's stillness, rather than ten? And also that you spend 16 hours out of 24 not lying down?
You don’t live your day to day life listening to soft music, lying down ready to doze. If your BP is elevated due to stress throughout the day it’s elevated, you will accumulate the harms. Idealizing conditions also gives a misleading reading.
> Now if you want to see I'm right, get up and walk around some and then sit back down and take another reading.
This doesn’t prove you’re right, just demonstrates normal physiology. Kind of like saying when you dyno an engine you should do it at idle. That is a valid measurement, just not the one that’s interesting.
In a healthy adult you will see a more significant increase in systolic pressure, but mean pressure shouldn’t rise nearly as greatly.
What you’re trying to observe is not the minimum ideal (your method) nor the short term maximums but an average of normal activity.
There’s a reason why ambulatory BP monitoring is the gold standard for diagnosing hypertension.
I've heard that for some people it's exactly the opposite. Standard procedure, IIRC, is to have the arm resting in a position that puts the cuff right about even with your heart. But some people get really big jumps in BP when supine, and I've heard it suggested that doctors might want to start doing their BP tests in that position because those people may not get diagnosed correctly despite spending a third of every day with high blood pressure.
I'm always amazed at how many nurses take your BP with your legs hanging off of the side of a table, back unsupported.
I've never seen a nurse not insist on the right position.
However I've always wondered how much of a difference my long torso makes when my blood pressure is measured. I'm 6'3", and it's mostly torso. The result is that a table that is the right height for most people, is low for me. And adjusting the table to match my body is something that I've seen a lot of variation on.
Seems it would be easy to equip exam rooms with a set of basic foam blocks that could help with patient positioning for this and other routine procedures.
Can any medical professionals chime in on how it's usually done for tall folks?
"Long torso body type" is, in general, an under-appreciated factor in ergonomics and product design, IMO.
A couple of off-the-cuff examples:
-The longer your torso, the worse a laptop computer affects your neck and posture. For long folks, upright posture requires keyboard and monitor to be vertically separated even more than most off-the-shelf monitor/desk/keyboard trays will allow. So a monitor hinged directly to a keyboard is the worst of all possible configurations.
-Most recent automotive seats seem to force the head forward, excessively curving the spine, and the longer the torso the worse the effect.
On the opposite side of the bell curve, a safe driving position is hard to achieve for drivers around 5ft tall and under. Correct/safe distance from airbags and pedals seems to be overlooked for those of shorter stature.
I wish solving problems experienced by body proportion outliers was a higher priority for product companies.
Why are recent auto head rests doing this? I hate it and I am nearly to the point of removing the head rest when I drive (but maybe that has downsides in an accident scenario).
Add clothes to that list. It's such a pain in the butt to find shirts made for people who are long torso without ending up with a shirt that's larger in every other dimension too. Even ones specifically labeled 'tall'
You need to find brands that have a slim sizing variation, coupled with a tall sizing variation. Ex j crew pre private equity, had good slim tall offerings.
I am a skeptic about the diagnostic criteria for hypertension, and especially about low targets for management. Cochrane did a meta review not long ago that made it sound like the signal was pretty weak below about 160/100 (as you might expect, if the measurement wasn't very accurate, which I don't think it is). I'm not saying it's not dangerous at much higher levels, but if you're freaking out at 140/90 because a chart says STAGE TWO, imo you can take a chill pill.
https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD...
(Disclaimer - I am not A doctor, and I am definitely not YOUR doctor, just an interested party who thinks the science smells funny.)
As a just-in-time bordering on chronically late individual (typical engineer), sprinting on foot or bicycle to the doctor’s office has led to some unusually high reading.
Putting aside the implementation technicalities, which I know nothing about, I'm convinced that markedly superior outcomes will be driven by something (e.g. watch-like devices) that captures entire weeks worth of regular BP readings across all times of day and night to provide a significant body of data.
I was also fed up with inaccurate readings, and was trying to prototype a medical device that would have an adjustable cuff based on arm size. I ran it by my concierge doc, but apparently the latest tech is to use light waves to measure BP, similar to how wearables are doing pulse OX and Heart Rate. The technique is known as Photoplethysmography (PPG).
There are devices that are sold with various swappable cuff sizes.
Only time I ever recall a nurse that insisted on doing BP measurements wrong was .. in jail. And not like all the nurses there, just this one person who did not care about anything besides flirting with corrections officers and getting the hell out of there ASAP.
What a world we live in. Dangerous times.
> "If you are consistently measuring blood pressure with an unsupported arm, and that gives you an overestimated BP of 6.5 mmHg, that's a potential difference between a systolic BP of 123 and 130, or 133 and 140—which is considered stage 2 hypertension,"
Okay, but that's a small and borderline difference?
I can lower the results by 10-20 points just by breathing deeply during the reading.
Yes, everyone can do that to some extent.
4~7 mmHg isn't going to make or break a hypertension diagnoses. 20~30 mmHg definitely.
This shouldn't be downvoted.
If you're +-7 in your reading, don't panic yet. If you're there with a stage 1 or 2 hypertension diagnosis (130-140+ systolic), the margin of error discussed in this article isn't necessarily meaningless, but remarkably close to it - you need to address an issue there.
More as a PSA for you hardworking programmers and IT managers out there: if you have chronic hypertension, address it sooner than later. If you think to yourself that you'll start jogging daily starting next week, and your doctor is giving you the option for meds, just get on the damn meds. If you start an exercise regimen that can quantifiably manage it without the meds later, great. Don't let the perfect be the enemy of the good. Hypertension is the silent killer, and before it kills it contributes to all sorts of other bad problems and conditions.
Hypertension can also make you feel like crap. It made my chest feel tight, which did not help my anxiety.
Yeah, I empathize. Glad you're doing better now, assuming you are. I would get awful headaches and nausea (like hide in a dark room, photophobic, overly sensitive to sound, smells, wishing I could chop my head off). For years I didn't connect the two. Felt like getting the worst two-day hangover without having drank anything, but if I had measured my blood pressure at the time it would have been well over 150. I clocked in at 170 during one of those episodes when I went to urgent care. For years I had just dismissed as having overdid it the prior week and just needed to rest. Even if you can put up with the pain like a badass, it's not healthy for your system to be redlining so often. It does its damage in the aggregate.
Pressure cuffs are sensitive to many factors outside blood pressure and are are pretty imprecise: news at eleven!
Wearing a waffle pattern shirt can also make the reading high. My blood pressure is 20 points higher if I wear a waffle pattern shirt than if I take it off.
That sounds like the guy who thought he had a leather allergy because whenever he woke up with his shoes still on he had a terrible headache and felt nauseous.
every time I get my blood pressure measured, my arm hangs on some scaffolding thing the blood pressure cuff hangs from. not even an armrest. Height is also not really standard.
that said, arm was not in my lap, and not hanging freely at my side.
I’ve never seen a discussion how ‘reactive’ one is physiologically either when discussing BP. That is, is one the kind of person who is generally calm throughout the day, or is one who has larger swings based on various stimuli? I’ve had readings as high as 155/95 when stressed rushing to a doctor’s office visit and readings as low as 105/62 when calmer. I suspect blood pressures varies wildly through the day, and this variation depends on a person’s physiology.
>I’ve never seen a discussion how ‘reactive’ one is physiologically
Then you have never looked for it. This is pretty basic stuff taught in the very first year of the medical school.
>when stressed rushing to a doctor’s office visit
Even has a name: white coat hypertension.
>I suspect blood pressures varies wildly through the day, and this variation depends on a person’s physiology.
Yes it absolutely does. Just like your heart rate varies throughout the day, your BP keeps changing as well. That's why we like to measure it over 24 hours before any diagnosis.
I had a major heart scare when I was 39 so I’m quite obsessed with my blood pressure. This is anecdata based off of my own experience with my heart, brain and body.
(Note that this is based off of someone capable of developing a heart problem in his late thirties so hopefully none of this will apply.)
Before I started running for fun, running up to a doctor’s office would absolutely spike my blood pressure. That was a combination of anxiety (which is/was an issue), cardiovascular health and basic physical reactions to exertion. Since I started running for fun, that relationship has completely changed. I don’t get the anxiety based blood pressure changes because I find running really fun and rewarding.
When I lift weights, my blood pressure will read a little higher for at least 24 hours after. The heavier I lift, the more my blood pressure will lift. I see a similar relationship with volume, but it’s not as linear as weight. So if I have to do fifty total reps to failure my blood pressure will be higher, but not as high as if I had done ten total reps to failure.
Food and alcohol have tremendous impacts. Cannabis has an impact but nowhere near the impact of either food or alcohol. Armed only with blood pressure data, I could make a good case for fast food and beer to be illegal. My case wouldn’t be as strong for cannabis. Caffeine is really fucking weird - it increases blood pressure up to the point of addiction. Then, not feeding the addiction will spike my blood pressure even more.
And I haven’t even begun to talk about how heavily my brain is involved. I dealt with undiagnosed ADHD through developing some very obsessive habits. As a consequence, I can quite literally obsess my way back to blood pressure medication.
Judging by how much personal data I have on my blood pressure, I’m sure you’re very surprised that I tend to be obsessive. :)
So anecdotally, you are 100% correct. But I can add some more anecdotes to hopefully ease your mind. When I got out of the hospital, I had to promise my cardiologist three perfect readings a day; meaning that I would religiously check my blood pressure at the same three times each day. Needless to say, I checked it way more than that. But there is an awareness that different levels of need require different levels of scrutiny.
The only part I still wonder is if my cardiologist knew that giving an obsessive person metrics would lead me into running. This may have just been a way to get me back into shape.
Automated BP cuffs painfully over-inflate; my BP is 20+/15+ higher when they're used.
I ask nurses to take my BP manually.
I had a similar issue, which was remedied by getting a larger cuff. In retrospect it makes sense that one size does not fit all, and apparently my biceps are on the larger side.
Cuff sizes are targeted to a range of arm sizes. The range should be stated either on the cuff or in the manual. Using improper sizes over/underestimates the pressure values.
Hmm, I find that the tighter the cuff goes, the lower my reading goes...
Real-life medical practice is basically going through the motions, then intuitively guessing the issue, prescribing something common since most cases are so banal and next patient please.
Engineer-minded people can discover lots and lots of such "obvious" issues in healthcare and of course the answer isn't that nobody would've guessed it, it just doesn't matter. Healthcare (outside of very specific diagnosable illnesses) is 90%+ medicine theater. People expect some pills, they want a few words with someone in a white coat, and their problem goes away usually by itself. Chronic persistent issues without obvious cause befuddle docs and they often don't find anything even after lots of tests.
Our better health and longevity today is more due to better work conditions, better food, better sanitation and food preservation, basic vaccines, basic disinfectants, basics like penicillin, smoking less etc. And the low hanging fruit to improve further is lifestyle: eating/drinking fewer calories (especially less sugary stuff), exercising/sleeping more and having better social connections. None of it is particularly arcane or in need of precise measurement.
> Engineer-minded people can discover lots and lots of such "obvious" issues in healthcare
It is a defining characteristic of "engineer-minded people" to think they understand better than others. Amusingly, they won't pretend to repair their car engine better than a mechanic, but they will strongly believe they understand all the bad tricks and failings of doctors. They almost never understand that current medicine is mostly experience and not hard science. Future medicine is science. 2024 medicine is not, and cannot be.
Honestly I'm not sure what a single point-in-time reading even accomplishes. I've been hooked up to a continuous blood pressure monitor a few times and it's always fun to see how low I can get it. It seems pretty useless without seeing where it fluctuates over time not in a doctor's office.
How do these work? You can't stay compressed all the time? Is it intravenal?
Once, when hospitalized, I had an arterial BP monitor that was continuous. The last systolic number I remember seeing before passing out from sepsis was in the 70s.
The ones I've been hooked up to just compress every few minutes so not terribly fancy.
Yet another medical topic being discussed on HN, with comments full of disinformation and skeptics that think they've noticed something new that doctors have missed. Remember people, don't take medical advice from HN.
Those topics are fascinating. They reflect how a pretty well-educated population subset thinks about healthcare. It's almost always entertaining!
Definitely increases my BP though. Imagine someone ignoring their own health problems because they believed what a HN commenter said.
Well, it's clearly an echo chamber. There's very little actual transmission of knowledge in those topics. It's almost always about confirming pre existing beliefs. I'm an MD too, but I've been raised by scientists. Scientists in my own family entertain the same beliefs exhibited by HNers, to surprising extremes such as dismissing the effect of even very well understood drugs.
Last year, my father stopped his blood pressure meds and was very surprised when I could guess he'd stopped just by looking at him, then proceeded to explain how the drugs acted, and got even more surprised when he got much better 15 min after taking them again. Since then, he totally forgot about this event and is in complete denial. You can't change beliefs by explanation. People have to get to their own conclusions, otherwise you're just fighting windmills all the time.
Nice to see a fellow MD (very possibly older and more experienced than me) on HN.
>he totally forgot about this event and is in complete denial.
I can never understand this, especially with well educated people like your father or mine. I can't get mine to agree to go see a doctor (other than me - he doesn't believe me when I tell him something about medicine) for anything, even when there are obvious problems with his health.