Essential
- High blood pressure is the main risk factor for premature death and several cardiovascular diseases.
- Up to 30 % of high blood pressure cases could go unnoticed due to imprecisions when it is measured by blood pressure, according to a study.
- The researchers discovered a way to limit errors when taking blood pressure.
Stroke, heart disease, infarction … Highter blood pressure (HTA) is a risk factor for many diseases. Diagnosing it quickly and effectively is therefore essential. However, up to 30 % of hypertension cases could go unnoticed due to errors and inaccuracies when measuring the tension.
A study by researchers from the University of Cambridge explains the origin of the inaccuracies of blood pressure readings based on the armband and how to avoid them. Their work was published in the journal PNAS NexusAugust 12, 2025.
Blood pressure measurement: systolic pressure can be underestimated
In the majority of cases, blood pressure is measured with the auscultatory method. That is to say the use of a armband provided with a pressure gauge which makes it possible to visualize the pressure exerted by the swelling of the pocket. Kate Bassil, co-author of the study, confirms that this type of measure is a reference in cardiology. But, “It overestimates diastolic pressure, while systolic pressure is underestimated”.
To understand this phenomenon, the researcher and her colleagues built a simplified physical model to isolate and study the effects of the blood pressure downstream, that is to say the blood pressure in the part of the arm located under the armband. “When the latter is inflated and the blood flow to the forearm is interrupted, a very low downstream pressure is created”explain the experts. During the laboratory tests, the team noticed that this pressure difference causes prolonged closure of the artery during the deflation of the armband. “Which delays the reopening and leads to an underestimation of blood pressure”. “We are not currently taking this error into account when diagnosing or prescribing treatments, which, according to estimates, can lead to the forgetting of up to 30 % of systolic hypertension cases”specifies Dr Bassil in a press release.
Hypertension: the simple gesture to reduce errors during the examination
The authors are considering several solutions to reduce these errors when taking blood pressure. One of them would be to raise the arm before the measurement in order to “Produce predictable downstream pressure and therefore a predictable underestimation”. The advantage of their proposal? There is no need for new devices, simply to modify the protocol of the auscultatory method.
“However, if new blood pressure monitoring devices are developed, they may require additional data correlated with downstream pressure, in order to adjust” ideal “values for each individual. These data may include age, BMI or tissue characteristics”specifies the team.
Researchers hope to obtain funding to check their results with patients, refine their calibration models and validate their effects on various populations.