# Why are they getting an "error" message? **URL:** \ **Category:** Factual Questions\ **Created:** [October 23, 2015, 11:50am UTC](https://boards.straightdope.com/t/why-are-they-getting-an-error-message/735525 "2015-10-23T11:50:12Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Brodi](https://avatars.discourse-cdn.com/v4/letter/b/cc9497/32.png) [@Brodi](https://boards.straightdope.com/u/Brodi)\ **Post date:** [October 23, 2015, 11:50am UTC](https://boards.straightdope.com/t/why-are-they-getting-an-error-message/735525/1 "2015-10-23T11:50:12Z")
I have for the past two months been in Cardiac Rehab for suspected Myocarditis. One of the things they do before you begin exercising is take your BP using an automatic BP cuff while standing. Seven times out of ten they can’t get a reading on me, an “error” message comes up. This rarely happens when I am seated. When they do get a reading, it is in the normal range. One nurse said she had trouble detecting the Korotkoff Sounds (“hearing” the arteries) in my right arm one time. My BP is normal to low and I am not on any medications. But, I do have Dysautonomia (problems with the autonomic system) and POTS Syndrome (Postural Orthostatic Tachycardia). So, why is this happening? ---
**Author:** ![Boyo\_Jim](https://avatars.discourse-cdn.com/v4/letter/b/87869e/32.png) [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)\ **Post date:** [October 23, 2015, 12:59pm UTC](https://boards.straightdope.com/t/why-are-they-getting-an-error-message/735525/2 "2015-10-23T12:59:26Z")
If they’re using the same machine every time it’s possibly an equipment failure. ---
**Author:** ![Hari\_Seldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hari_seldon/32/5173_2.png) [@Hari\_Seldon](https://boards.straightdope.com/u/Hari_Seldon)\ **Post date:** [October 23, 2015, 1:19pm UTC](https://boards.straightdope.com/t/why-are-they-getting-an-error-message/735525/3 "2015-10-23T13:19:37Z")
I don’t know but my doctor’s BP machine, which is supposed to take BP repeatedly over a 5 minute period seems to work on me but fail repeatedly on my wife. So maybe it is you for some reason. ---
**Author:** ![Kevbo](https://avatars.discourse-cdn.com/v4/letter/k/e47774/32.png) [@Kevbo](https://boards.straightdope.com/u/Kevbo)\ **Post date:** [October 23, 2015, 4:45pm UTC](https://boards.straightdope.com/t/why-are-they-getting-an-error-message/735525/4 "2015-10-23T16:45:37Z")
I found this article interesting: > **[Measuring blood pressure: pitfalls and recommendations](https://academic.oup.com/ndt/article/19/4/766/1810372)** > > 1Zentralkrankenhaus Reinkenheide, Medical Clinic II, Bremerhaven, Germany and 2Forschungsinstitut für klinische Medizintechnik, Asperg, Germany I lists a number of factors that influence the automated cuffs. They analyze the waveform of pressure variation coming from the cuff. The elasticity of the arteries, and how much, and what type of tissue your arm has can throw them off. I seem to pretty consistently be 10-12mm lower when measured with a manual cuff, vs. the automated ones. That was enough to be the difference between having my hypertension meds correct, and feeling dizzy and queasy. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [October 23, 2015, 7:56pm UTC](https://boards.straightdope.com/t/why-are-they-getting-an-error-message/735525/5 "2015-10-23T19:56:36Z")
I often get an error message on my home cuff unit. It seems to relate to the inflation starting - then after it’s inflated enough that it should sense a pulse, it is not sensing one. Usually I have to move or tighten the cuff… sometimes just restart. Sometimes the plug is loose and the air pressure is not high enough.