Sometimes Rising Blood Pressure Is an Effort

"Nobody ever told me why my blood pressure is high."

I often hear that the medicine was given but the reason was not. There is a reason for that.

For most of it, no single cause can be named

More than 90% of high blood pressure cannot be traced to one cause. Cases with a clear origin in the kidney or the hormones make up the remaining few per cent.

This does not mean there is no reason. It means it does not narrow to one. Several conditions have pushed it up together, so no single one can be pointed at.

The cases with a known cause give the clue

Look at the ones that can be traced, though, and a grain shows.

There is an old experiment. Narrow the artery going to the kidney and the blood pressure rises. Narrow other large arteries and it does not. The kidney senses that less blood is coming to it and sends signals that raise the pressure of the whole body.

Something can be read here. The rise was not a fault but an adjustment. From the kidney's side it was work done to secure its share of blood.

Pressure that protects something

Seen this way, blood pressure reads differently.

Blood pressure is the force that pushes blood out. So where blood is reaching somewhere less, the body will raise that force to get it there. It rises because vessels have stiffened, yes — but part of it rises because somewhere is not getting enough.

Whether something similar happens for the brain is being studied, though that side is still a hypothesis and the researchers say so themselves.

So it moves with conditions

If blood pressure is an adjustment, it should move when conditions do. It does.

For every 10 degrees the temperature falls, systolic pressure rises by close to 6 mmHg. And it does so not because the heart beats harder but because resistance at the periphery goes up. Tightening the vessels near the skin to keep heat in is itself a raising of whole-body pressure.

That summer and winter differ, that morning and night differ, that a poorly slept night differs — the same grain. (The Body Does Not Hold an Exact Number)

Even so, do not adjust medication yourself

Let me be plain here. None of this means medication can be reduced or stopped.

Whatever the reason, pressure held high for long puts a load on the vessels, the kidneys and the heart. Bringing it down is needed in its own right. Follow the judgement of whoever prescribed it.

What I am saying is that there is a place to look, separately from that.

What I look at in the consulting room

I look less at a single figure than at when, and under what conditions, it rises and falls. Which season is worse, which part of the day differs, how the sleeping is going.

And I look at whether somewhere is receiving too little. Whether hands and feet run unusually cold, whether long hours are spent seated, whether the neck and shoulders have set. Lowering the pressure and helping the flow are different pieces of work.

When to see a doctor first

If blood pressure rises sharply along with severe headache, chest pain, breathlessness or changes in vision — see a doctor at once, before a story like this.

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Sources

• Hypertension — an account of why most of it is essential, with no single cause identified — Asan Medical Center
• A piece setting out the view that when an organ receives too little blood the body raises pressure to make up for it — Future Cardiology, 2016

Written by Dr. Heo Ji-young (Ph.D. in Korean Medicine Pathology, Kyung Hee University · former Research Professor of Herbology, Kyung Hee University)