What a blood pressure measurement is in reality

Seems a bit daft to post on this subject, but I struggled to find anything out on the web about what the numbers actually represent. There’s plenty of stuff telling you what values are high, normal etc. but nothing about what is actually happening during the course of a measurement. But I found some documentation eventually, looks like it is aimed at clinicians, which I’ll try to explain.

You wrap the cuff around your upper arm. At that point, you’re over your brachial artery, so a direct route to the heart. The documentation I looked at made a big deal of this, so this is important.

The cuff inflates sufficiently high that it stops blood flowing. If you were listening with a stethoscope, you’d hear nothing.

You gradually let the pressure out of the cuff. Your heart pumps with sufficient pressure that, sooner or later, it overcomes the pressure in the cuff, and the blood starts flowing again. Again, if you had a stethoscope, you’d hear the heart beating. When blood first starts flowing, this is the systolic blood pressure – the pressure when the heart beats.(

You keep releasing pressure from the cuff. You can still hear the heart beating. Again, sooner or later, you stop hearing anything. At that point, this is the diastolic blood pressure. Basically the pressure in the cuff is sufficiently low that your heartbeat can’t be heard. It’s the pressure when your heart is resting. In my simple world, I think of the heart as a machine which is either on (pumping) or off (resting). In this scenario, at any rate.

I mean, a stethoscope is just one way of detecting these signals. I would imagine an electronic machine would detect these points by “feeling” when the pulse starts and stops (a momentary slight increase in pressure, say, as the heart pulses). I think my next task is to find this out.

I’ve tried to explain this briefly and in layman’s terms. If you feel i could do better, please leave a comment, or there’s a link at the bottom of the page which you can use to contact me.

Blood Pressure

I don’t much mention my blood pressure, but it has always been high and I have taken medication for it for several years. I used to worry more about my blood pressure than I did my diabetes, although these days I just take the meds and think “que sera sera”.

In fact the only two things in my life which have ever been abnormal (i.e. non-average readings, I hate the word “normal”) are my blood pressure and my diabetes. So, when looking for the causes of the stroke, these are prime candidates. Indeed, after the stroke, all of my meds were changed – and I can’t help thinking that the meds I took before the stroke were not the most appropriate for me. But my blood pressure, certainly, is a lot lower now than then, back into a recommended range.

These days, I keep tabs on both my sugar and my blood pressure. With my diabetes, I can take the insulin and also balance my sugar levels with what I eat, plus I measure it daily so have many results. With the blood pressure, it’s not as easy. I can take the meds, but there’s not much else. I can’t get the exercise I once did because of my disability, and frankly, even when I cycled hundreds of miles per month, it didn’t make much difference. I used to keep sufficient tabs on things even then, to know that. So I’m kind-of left thinking that if a stroke is gonna happen, it’s gonna happen. Plus, because there’s not as much I can do, I measure it monthly, approximately.