Does faint blood pressure read high on machines?
July 12, 2017 5:33 PM Subscribe
You are not my doctor, but I need help articulating what I've got going on in the blood pressure department.
I am a 37 year old male. I've habitually had high blood pressure in the 13X/9X range and a very fast heartbeat (90 bpm). I've had those values since at least my mid 20s when I started noticing the measurement value. I've had consistent values from when I was 50 lbs lighter and much more active all the way through my current largely sedentary lifestyle. If you met me, you'd probably think I am in fair to good shape for a person my age.
I was just at the doctor's office, and both the nurse and the doctor read my blood pressure as 120X/7X, using the squeezebulb arm cuff and stethoscope method. I was shocked! They both also said it was "faint". When I got home I used my auto-blood pressure reader, and it read 130X/9X like usual.
It then occurred to me that almost all of the blood pressure measurements I've had over the years has been from an automated device, including at several doctor's offices.
Is it a thing that my "faint" blood pressure just causes the machines to read high, and I don't actually have high blood pressure? I've taken Lisinopril for 6 months now and it has had zero effect on the reading. If you know anything about this sort of thing, please let me know what I should be saying to my doctor.
What does faint blood pressure mean?
(EKG, bloodwork, and urinalysis all came back normal except that my cholesterol could be better and my a1c is a bit high.)
Thanks hivemind! I'm doing the bee dance for love atcha!
I am a 37 year old male. I've habitually had high blood pressure in the 13X/9X range and a very fast heartbeat (90 bpm). I've had those values since at least my mid 20s when I started noticing the measurement value. I've had consistent values from when I was 50 lbs lighter and much more active all the way through my current largely sedentary lifestyle. If you met me, you'd probably think I am in fair to good shape for a person my age.
I was just at the doctor's office, and both the nurse and the doctor read my blood pressure as 120X/7X, using the squeezebulb arm cuff and stethoscope method. I was shocked! They both also said it was "faint". When I got home I used my auto-blood pressure reader, and it read 130X/9X like usual.
It then occurred to me that almost all of the blood pressure measurements I've had over the years has been from an automated device, including at several doctor's offices.
Is it a thing that my "faint" blood pressure just causes the machines to read high, and I don't actually have high blood pressure? I've taken Lisinopril for 6 months now and it has had zero effect on the reading. If you know anything about this sort of thing, please let me know what I should be saying to my doctor.
What does faint blood pressure mean?
(EKG, bloodwork, and urinalysis all came back normal except that my cholesterol could be better and my a1c is a bit high.)
Thanks hivemind! I'm doing the bee dance for love atcha!
My guess is that it isn't your blood pressure that is "faint," but the sound of your pulse in the stethoscope (and I just learned those are called Korotkoff sounds!).
Automatic blood pressure devices sense vibrations from your blood vessels instead of sounds (article). Theoretically, I can see how faint vibrations could lead to high diastolic readings. The machine inflates to a high pressure, high enough to stop blood flow (and thus vibrations). It slowly deflates until it senses vibrations again: this is your systolic pressure. Then it deflates more until the vibrations go away again: this is your diastolic pressure. At least on the diastolic side, if the machine thinks the vibrations went away before they really did, it would overestimate pressure. I'm less clear on why the systolic pressure might read high, though.
posted by snowmentality at 7:37 PM on July 12, 2017 [2 favorites]
Automatic blood pressure devices sense vibrations from your blood vessels instead of sounds (article). Theoretically, I can see how faint vibrations could lead to high diastolic readings. The machine inflates to a high pressure, high enough to stop blood flow (and thus vibrations). It slowly deflates until it senses vibrations again: this is your systolic pressure. Then it deflates more until the vibrations go away again: this is your diastolic pressure. At least on the diastolic side, if the machine thinks the vibrations went away before they really did, it would overestimate pressure. I'm less clear on why the systolic pressure might read high, though.
posted by snowmentality at 7:37 PM on July 12, 2017 [2 favorites]
The manual BP is more accurate. They probably had poor word choice when they said "faint" - a BP that is 120s over 70s is absolutely normal. Agree with snowmentality's more detailed explanation of how BP machines work. Make sure your home cuff is the right size for you and you are putting it in the right place on your arm. You might want to bring it to your doctor's office for a demo.
posted by treehorn+bunny at 8:20 PM on July 12, 2017 [1 favorite]
posted by treehorn+bunny at 8:20 PM on July 12, 2017 [1 favorite]
I also suspect that your nurse and doctor were probably referring to the Korotkoff sounds when they used the word "faint;" what they may have been trying to communicate is that your BP was hard for them to read. When the Korotkoff sounds are not very loud, it's easy to doubt your reading; it makes you wonder whether you might have missed the first or last thump. This might be why both your doctor and nurse took your BP. Whoever took it first may have asked the second one to re-take it to confirm because they felt they only heard "faint" sounds and wanted to check against someone else's judgment. Could this accurately describe the conversation/interaction during your appointment?
In terms of the automated cuff at home, yes the manual BP (aka sphygmomanometer) is more accurate, and more than that, some individual automated blood pressure devices may run either high or low consistently. I'm not sure if the error of automated machines is at all related to whatever causes "faint"-ness on manual readings. Personally, when taking a manual BP, I find that "faint" Korotkoff sounds are more likely to lead to a lower-than-accurate reading than a higher-than-accurate one, but again, that's manual, not automatic. (I am a nursing student.)
posted by snorkmaiden at 9:38 PM on July 12, 2017 [3 favorites]
In terms of the automated cuff at home, yes the manual BP (aka sphygmomanometer) is more accurate, and more than that, some individual automated blood pressure devices may run either high or low consistently. I'm not sure if the error of automated machines is at all related to whatever causes "faint"-ness on manual readings. Personally, when taking a manual BP, I find that "faint" Korotkoff sounds are more likely to lead to a lower-than-accurate reading than a higher-than-accurate one, but again, that's manual, not automatic. (I am a nursing student.)
posted by snorkmaiden at 9:38 PM on July 12, 2017 [3 favorites]
Anecdata, but when I was recently hospitalized for a congenital heart issue they finally had to take me off the automated blood pressure cuff because it couldn't read my blood pressure and kept giving off the "dangerously high" alarm. A nurse would rush in and do a manual pressure and find it to be 100/70, just like it always is at the doctor's office.
posted by xyzzy at 10:53 PM on July 12, 2017 [1 favorite]
posted by xyzzy at 10:53 PM on July 12, 2017 [1 favorite]
Doctor here. I wouldn't typically use "faint" to describe a pressure of 120s/70s. If there is more tissue (fat, muscle) between the artery and the stethoscope, I guess that could make Korotkoff sounds fainter... Are you overweight or especially muscle-y?
But regardless, the manual method is the most accurate. We use the machines in the office because they save time and are usually close enough. (Home machines, being cheaper, are notoriously inaccurate.) In this case, it sounds like both your doctor's machine and your home cuff need to be recalibrated.
posted by basalganglia at 3:09 AM on July 13, 2017 [2 favorites]
But regardless, the manual method is the most accurate. We use the machines in the office because they save time and are usually close enough. (Home machines, being cheaper, are notoriously inaccurate.) In this case, it sounds like both your doctor's machine and your home cuff need to be recalibrated.
posted by basalganglia at 3:09 AM on July 13, 2017 [2 favorites]
I agree that it sounds like they were talking about the Korotkoff sounds being faint. Thinking it through, I'm not sure this is related to the machine's measurement being high. The way I understand it, just like manual BP measurements, the machine adds a lot of pressure at the beginning, then slowly bleeds it off, "listening" for the Korotkoff sounds. It is "hearing" these sounds earlier (i.e., at a higher BP) than your nurse and doctor. So the options are (1) the machine is calibrated correctly but is hearing something phantom at 13X/9X that your nurse/doctor did not hear or ignored, or (2) the machine is calibrated incorrectly and is hearing your actual Korotkoff sounds, but just thinking the pressure is higher than it is. (2) seems more believable, but either way it points towards a problem with the machine.
posted by dondiego87 at 4:25 AM on July 13, 2017
posted by dondiego87 at 4:25 AM on July 13, 2017
I've taken Lisinopril for 6 months now and it has had zero effect on the reading.
I'm curious why you think this is so? It sounds like your blood pressure at your most recent visit was lower than your baseline -- your anti-hypertensive medication is a reasonable suspect for causing that.
For what it's worth, at the clinics where I've seen patients, we would not start someone on new hypertension meds without a manual blood pressure reading, for all the reasons described above. I'm sure plenty of people don't go by this practice, but I would be really shocked if you've never had a manual reading before.
posted by telegraph at 5:19 AM on July 13, 2017 [4 favorites]
I'm curious why you think this is so? It sounds like your blood pressure at your most recent visit was lower than your baseline -- your anti-hypertensive medication is a reasonable suspect for causing that.
For what it's worth, at the clinics where I've seen patients, we would not start someone on new hypertension meds without a manual blood pressure reading, for all the reasons described above. I'm sure plenty of people don't go by this practice, but I would be really shocked if you've never had a manual reading before.
posted by telegraph at 5:19 AM on July 13, 2017 [4 favorites]
Nurse here. Endorsing other comments that your home cuff likely off. That's normal with these products. But also want to add that your pulse is not especially fast and 130s over 90s can use some work but is also not alarming. Hypertension is consistently 140/90 or above.
So it's a great idea to get physically active again, make sure to eat your veggies, and reduce stress. And know that everyone's blood pressure goes up with age, so increasing physical activity now is a great idea, but also you're pretty darned normal.
posted by latkes at 8:40 AM on July 13, 2017
So it's a great idea to get physically active again, make sure to eat your veggies, and reduce stress. And know that everyone's blood pressure goes up with age, so increasing physical activity now is a great idea, but also you're pretty darned normal.
posted by latkes at 8:40 AM on July 13, 2017
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posted by brook horse at 6:41 PM on July 12, 2017 [1 favorite]