Blood pressure in women, and why it changes after 55

Blood pressure gets treated as a score you pass or fail. It is better understood as a reading on how flexible and healthy your arteries are, which is why it matters far beyond the heart.

As a rough guide, around 120/80 or below is where most people want to be. Between about 120 and 129 on the top number is usually called elevated, a signal to change something rather than a diagnosis. From 130/80 upward is generally treated as high blood pressure. Your own targets may differ, and your doctor sets them, not a website.

For a long time the research that shaped these thresholds was done largely in men, and the numbers were applied to everyone. More recent work suggests women's cardiovascular risk may begin climbing at lower pressures than men's, somewhere nearer 110 than 120 on the top number.

The official thresholds have not changed on the back of that. The practical message has: if you have been told your blood pressure is only slightly high, that is not a reason to relax about it.

Oestrogen keeps blood vessels relaxed and flexible. When it falls, arteries stiffen, and several other things shift at the same time: more fat carried around the middle, muscle quietly lost year on year, the body responding less well to insulin, and the kidneys holding on to salt more readily than they used to.

That last one is worth dwelling on. Two women can eat identical amounts of salt and see very different effects on their blood pressure, and salt sensitivity generally rises after menopause. If cutting salt seems to matter more to you than it used to, you are not imagining it.

Stiffer arteries also change the shape of the reading. A widening gap between the two numbers, something like 160 over 70, is itself a sign of stiffness rather than a reassuringly low bottom number.

Many older women have a high top number with a perfectly ordinary bottom one, and it gets dismissed on the strength of the second figure. That is the wrong way round.

Past about 60, the top number is the better predictor of stroke, heart failure and cognitive decline. If yours is high and the bottom is fine, that still deserves attention.

This is the fact that surprises women most, and almost nobody is told it. High blood pressure during pregnancy, pre-eclampsia, or diabetes that appeared while you were pregnant all predict a higher lifetime risk of high blood pressure, stroke, heart and kidney disease, decades later.

Pregnancy works rather like a stress test for the heart and blood vessels. If yours flagged something forty years ago, that information is still relevant now, and it is worth telling your doctor even if nobody has ever asked.

You will usually feel completely well while high blood pressure is doing its damage, which is why it can only be caught by measuring rather than by noticing.

And it is not only about the heart. Sustained high pressure damages the brain, raising the risk of stroke, vascular dementia and gradual cognitive decline, as well as the kidneys and the small vessels in the eyes. What is good for your heart really is good for your brain.

Sleep belongs here too. Broken sleep and sleep apnoea become more common after menopause, often without the loud snoring people expect, and poor sleep pushes morning pressure up.

Move, most days, and in company if you can manage it. Build and keep muscle, because working muscle releases messengers that relax blood vessels and improve how insulin works. Eat for it: enough protein, plenty of fibre and potassium from vegetables, fruit and pulses, and less salt from packets. Mind your sleep and your stress. And measure, because nothing else on this list tells you where you stand.

Home readings are worth taking, since clinic readings can run high simply because you are at the clinic. Take them at the same time of day, sitting, after a few minutes of rest, and write them down.

This page is for understanding your readings, not for diagnosing or treating yourself. If you take medication for blood pressure, none of this replaces it, and stopping is a decision only your doctor should make.