A few years ago I was diagnosed with primary hypertension (I10). The diagnosis introduced me to a world of medicine I never knew. And here I want to write about the question I have asked myself ever since: what’s my blood pressure?

Me being me, after hearing that I have hypertension, I consulted the diagnostic criteria of hypertension and discovered that treatment criteria are different from diagnostic criteria. And the figure of 150/100 which I was given was, in fact, a treatment criterion (is it to reduce the number of people in treatment?). Also, smitten by clarity of disease starting point, I started asking the question when depression starts, which resulted in an article (full text here). Incidentally, it was the most rejected article in my career (rejected 5 times) – with the most aggressive and insulting reviews I have ever experienced (including a psychiatric diagnosis; yes, seriously).

I also discovered that the medication I was offered in the UK was (apparently) so old that in my native Poland no one was prescribing it anymore. But the one prescribed in Poland was deemed too expensive in the UK.

But this is not what I want to write about. I want to write about the question “what is my blood pressure?”. Before I was diagnosed, I was asked to invest in a blood pressure monitor and start taking my blood pressure (and report back to the doctor). And so I did. After taking advice and investigating, I decided to go for the top-of-the-range model. I bought it and the fun started.

The advice I got from a doctor was that I was supposed take my blood pressure three times, reject the first measurement (which sometimes was the lowest of the three, paradoxically), and then record the lower value of the remaining two, at different times of the day, always resting a bit before taking measure. I must admit that I was wondering about the procedure, but I followed the advice.  Why take three measures? Isn’t my blood pressure just my blood pressure, I asked myself?

It turned out it’s not. The three measurements always gave different results, sometimes significantly (commonsensically speaking) different. As I was observing them, I decided to investigate further. I would sit and take 10 measurements, 15 measurements (sometimes with my children looking on with increasing suspicion), I probably never went beyond 20. Not that I didn’t want to, but I thought I would myself become suspicious of myself. I did that many times, recording every measurement and, to my increasing surprise, hardly ever did I have a repeated value. Usually, all 15 measurements would yield different values and if someone asked me what my blood pressure was, I could not answer.

As I am quite resigned to the fluidity of the world I live in and I am also aware that sometimes things cannot be measured at all (Mr Heisenberg took care of that), so the ever-changing blood pressure was just another interesting factoid and, to be honest, it didn’t worry me that much. Unfortunately, the knowledge raised another question. Every time I am asked by a medic what my blood pressure is, I start wondering what to say (no, I do not usually share my measurement problems – I’m not stupid). But I wonder even more when a doctor actually makes a note of my blood pressure. For example, some time ago, I was late for an appointment, so I ran up the stairs. Within a minute of my visit with the doctor, he took my blood pressure. He took it once, never asked me whether I was in a hurry. He took it, moreover, with a wrist monitor (which, I was told, are notoriously unreliable, but easy to carry). My blood pressure was (predictably) quite high and so I heard a lecture about high blood pressure. No, he didn’t ask me whether I was on antihypertensive medication, either, and I could not be bothered to tell him. I know, go figure – clinical communication for you! Still, he made a record of my blood pressure value and I was wondering what exactly he recorded.

There are at least three morals to be had here, I think. The first moral is about a clash of my expectations and ‘reality’. My expectation was that my blood pressure was simply ‘a value’. When I stopped to think about it, it made some sense that it was not (unless I am dramatically ill, except I don’t know it). I wish someone had told me. Though, I was not particularly worried, I could have been. Second, I do hope that when you, doctor, make a record of my blood pressure, you do know what that you are recording uncertainty. I hope you understand it and can deal with it. Third, can you, (pretty) please, stop asking me what my blood pressure is. Because it seems the only viable answer to that question is ”Who (…) knows?”