Emily Chan
Millions of people may be getting misdiagnosed with hypertension because of the way their arms are positioned during a blood pressure check.
A new study suggests that common arm positions, such as resting your arm on your lap or letting it hang at your side, can throw off blood pressure measurements by a significant amount.
Researchers at Johns Hopkins University discovered that the wrong arm position could result in 54 million Americans being told they have high blood pressure when they actually might not.
Guidelines state that your arm should be supported on a table or desk at heart level. However, this arrangement is not always accessible or followed in many doctor’s offices, clinics, and hospitals.
In the new study, 133 adults between the ages of 18 and 80 in Baltimore were selected as participants.
Their blood pressure was measured several times in different arm positions. The positions included being supported on a desk, resting on their lap, and hanging at their side.
The participants had their blood pressure taken three times in each position. Between each set of measurements, they were allotted a rest period and a short walk to control for individual variations within the same person.
Both the systolic blood pressure (the top number) and the diastolic (the bottom number) were inflated by about four points when participants had their arms resting on their lap.
When their arm hung unsupported at their side, the discrepancies were even greater. The systolic was overestimated by about seven points, while the diastolic was by 4.4 points.
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