Blood pressure readings (hypertension) - how to interpret them?

[Marco]

I've had my blood pressure tested many times over the years, most recently within the last few months, and no-one has ever mentioned it as an issue, I wasn't concerned about it and I assumed my BP was probably low as, especially in the early days, I tended to be a 'frequent fainter'. Nowadays I just get a constant feeling of pressure and lightheadedness.

I did come across this (2002) review that suggests that the interpretation of what constitutes 'high blood pressure' and what measures best predict risk isn't straightforward.

Systolic vs diastolic blood pressure and the burden of hypertension

Introduction

How do we best define hypertension? It is still uncertain whether it better defined (say) as a systolic blood pressure (SBP) 140 mm Hg, a diastolic blood pressure (DBP) 90 mm Hg, either or both. Applying either criteria or both, implies the existence of different 'types' of hypertension, such as systolic-diastolic hypertension, isolated systolic hypertension or isolated diastolic hypertension

.

….... Examination of data from Framingham and Framingham Offspring studies showed that DBP vastly underestimates the number of patients requiring treatment

http://www.nature.com/jhh/journal/v16/n3/full/1001373a.html

Effectively you have two measures of blood pressure. The higher (systolic) reading refers to the blood pressure during the heartbeat and the lower (diastolic) reading is the pressure in between heart beats. Rather surprisingly (to me) it has tradtionally been a sustained rise in the lower diastolic measure that is considered a cardiovascular risk factor. Presumably because this is considered more representative of the basal 'tone' of the cardiovascular system?

The review suggests however that the higher systolic reading may be at least as important as a risk factor and further that the magnitude of the difference between the two measures (the pulse pressure) may also be critical. As the quote above also suggests, both SBP and DBP can be elevated (or low) in isolation.

That being the case (potentially) and checking back on my records :

1993 – SBP = 138
DBP = 60

2001 – SBP = 130
DBP = 60

2005 – SBP = 130
DBP = 70

'Ideal' blood pressure is often given as below 120/80.

Under the traditional interpretation where SBP greater than 140 mm Hg and DBP greater than 90 is considered hypertension – but the distolic measure is of primary importance - then my DBP of 60-70 would be interpreted as low risk.

Putting the emphasis on the systolic blood pressure however would place me (130-138) well within and near the top of the 'at risk' of hypertension range of 120-140.

Further emphasis on the difference between the two measures (pulse pressure) would suggest that I was at higher cardiovascular risk in 1993.

OK – I know BP readings are variable and you really need to read the paper to appreciate the subtleties and caveats (including 'staging') but I'd hope that things are a little clearer since this review was written though I suspect not. Not that I intend to lose any sleep over this as I already know I'm not well and by the pulse pressure measure my BP parameters seem to have improved a little over the decades.

Interesting though?

 

[MeSci]

I've had my blood pressure tested many times over the years, most recently within the last few months, and no-one has ever mentioned it as an issue, I wasn't concerned about it and I assumed my BP was probably low as, especially in the early days, I tended to be a 'frequent fainter'. Nowadays I just get a constant feeling of pressure and lightheadedness.

I did come across this (2002) review that suggests that the interpretation of what constitutes 'high blood pressure' and what measures best predict risk isn't straightforward.

http://www.nature.com/jhh/journal/v16/n3/full/1001373a.html

Effectively you have two measures of blood pressure. The higher (systolic) reading refers to the blood pressure during the heartbeat and the lower (diastolic) reading is the pressure in between heart beats. Rather surprisingly (to me) it has tradtionally been a sustained rise in the lower diastolic measure that is considered a cardiovascular risk factor. Presumably because this is considered more representative of the basal 'tone' of the cardiovascular system?

The review suggests however that the higher systolic reading may be at least as important as a risk factor and further that the magnitude of the difference between the two measures (the pulse pressure) may also be critical. As the quote above also suggests, both SBP and DBP can be elevated (or low) in isolation.

That being the case (potentially) and checking back on my records :

1993 – SBP = 138
DBP = 60

2001 – SBP = 130
DBP = 60

2005 – SBP = 130
DBP = 70

'Ideal' blood pressure is often given as below 120/80.

Under the traditional interpretation where SBP greater than 140 mm Hg and DBP greater than 90 is considered hypertension – but the distolic measure is of primary importance - then my DBP of 60-70 would be interpreted as low risk.

Putting the emphasis on the systolic blood pressure however would place me (130-138) well within and near the top of the 'at risk' of hypertension range of 120-140.

Further emphasis on the difference between the two measures (pulse pressure) would suggest that I was at higher cardiovascular risk in 1993.

OK – I know BP readings are variable and you really need to read the paper to appreciate the subtleties and caveats (including 'staging') but I'd hope that things are a little clearer since this review was written though I suspect not. Not that I intend to lose any sleep over this as I already know I'm not well and by the pulse pressure measure my BP parameters seem to have improved a little over the decades.

Interesting though?

Very interesting - thanks, @Marco. This is something I often think about. I was extremely hypertensive (systolic and diastolic) in 2005-7, then perindopril, an ACE inhibitor, was prescribed and controlled it well much of the time but not always, and I have now found that it probably caused my severe bouts of hyponatraemia, as discussed in this thread, so am planning to switch to a beta blocker when I have finished collating my test results.

I have noticed some people talking about needing to increase their pulse pressure, notably @Valentijn. IIRC this is in the context of hypotension.

My pulse pressure has been increasing recently.

Re variability, I usually take 3 readings over the course of a few minutes. It often varies a lot even over that time.