Not uncommonly in practice I see individuals who have a diagnosis of possible ‘hypertension’ (high blood pressure) hanging over their heads. Usually what has happened here is that a doctor has noted a high or borderline high reading, which has been ‘confirmed’ again on another visit. Perhaps not surprisingly, individuals can be quite uptight about the fact that they may have raised blood pressure. There’s a risk that this anxiety can push up blood pressure when being tested in a doctor’s office. The end result, sometimes referred to as ‘white coat hypertension’, is that readings taken in the clinical setting overestimate blood pressure, and possibly lead to unnecessary treatment and undue concern.
For this reason, when I see someone with a suspicion of raised blood pressure in practice, I tend to give two pieces of advice. These are that they might consider getting a self-test blood pressure monitor that they can use calmly and quietly at home. If this reveals consistently elevated readings, then it might be prudent to have further investigations (e.g. automatic 24-hour monitoring of blood pressure). However, if self-testing reveals normal blood pressures (as it very often does), then this basically puts the person in the clear for hypertension. Then they (and their doctor) can, generally speaking, stop worrying about it.
I was interested to read about a recent study in which the usefulness of blood pressure home-testing was assessed [1]. A group of 2000 men and women aged 45-74 were assessed over a 7-year period. During this time, the individuals measured their own blood pressure at home (with a Omron HEM-722c), and also had regular physical examinations including blood pressure measurement with a doctor. Over the course of the study, there were a number of fatal and non-fatal ‘cardiovascular events’ such as heart attacks and strokes.
It turns out that the home-measured blood pressure readings were a much better predictor of these events than the readings taken in the doctor’s office.
What level of blood pressure is healthy? Well, conventional advice is generally that blood pressure should be lower than 140/90 mmHg. The British Heart Foundation here suggests that blood pressure should be lower than 140/85, but “if you’ve had a heart attack, stroke, have diabetes or diagnosed with coronary heart disease, your blood pressure should be below 130/80.”
Some doctors have suggested that with blood pressure, “lower is better.” However, there is at least some evidence that this is not necessarily the case. See here for more about this.
References:
1. Niiranen TJ, et al. Home-Measured Blood Pressure Is a Stronger Predictor of Cardiovascular Risk Than Office Blood Pressure. The Finn-Home Study. Hypertension 12 April 2010 [epub ahead of print]
