Certain arm positions commonly used for blood pressure checks may lead to inaccurate results. Here’s the right way to do it

A new study found that having your arm in the wrong position during blood pressure checks — either at home or the doctor’s office — can result in readings “markedly higher” than when your arm is in the recommended position: appropriately supported on a table with the middle of the cuff positioned at heart level.

A new study found that having your arm in the wrong position during blood pressure checks — either at home or the doctor’s office — can result in readings “markedly higher” than when your arm is in the recommended position: appropriately supported on a table with the middle of the cuff positioned at heart level. This suggests that not consistently having your arm positioned and supported appropriately during a blood pressure reading might result in a misdiagnosis of high blood pressure, which some experts worry could possibly lead to unnecessary treatment. The study, published Monday in the journal JAMA Internal Medicine, found that having your arm resting in the lap during a blood pressure reading can lead to an overestimated systolic blood pressure measurement by 3.9 mm Hg and overestimated diastolic reading by 4 mm Hg. And having your arm hang by your side can lead to an overestimated systolic reading by 6.5 mm Hg and overestimated diastolic reading by 4.4 mm Hg. Blood pressure is measured in units of millimeters of mercury or mm Hg, which consists of two numbers – the upper or systolic reading and the lower or diastolic reading. A person is considered as having high blood pressure or hypertension if they have consistent readings of 130/80 or higher. “Health care providers need to be reminded about the importance of taking the time to do these steps properly,” said the study’s senior author Dr. Tammy Brady, who serves as vice chair for clinical research in the department of pediatrics at the Johns Hopkins University School of Medicine and medical director of the pediatric hypertension program at Johns Hopkins Children’s Center. “I just hope that it raises awareness regarding how important things like arm position are to blood pressure measurement accuracy,” Brady said about the study.