Accurate blood pressure readings depend on arm position: study

They are in the wings!

Researchers from Johns Hopkins Medicine say accurate blood pressure readings depend on proper arm positioning — and many patients and practitioners are getting it wrong.

In the study, published Monday in JAMA Internal Medicine, researchers compared the blood pressure readings of 133 adults who held their arms in three different positions: resting on their lap, resting on a surface, and hanging from their side. theirs. They found that certain placements corresponded to a drastic increase in systolic pressure.

Systolic measures the pressure in the arteries when your heart beats – represented by the first and highest number on a blood pressure reading.

The research team found that when participants had their arms hanging by their sides, their systolic blood pressure was 6.5 points higher and their diastolic blood pressure was 4.4 points higher.

Diastolic pressure, the pressure in the arteries between heartbeats, is the last number in the reading.

Lap support overestimated systolic pressure by 3.9 points and diastolic pressure by 4 points.

Dr. Tammy Brady — a pediatric epidemiologist and medical director of the pediatric hypertension program at Johns Hopkins Children’s Center — was surprised by her findings.

She noted that blood pressure discrepancies can result in hypertension being misdiagnosed and patients being prescribed medications they don’t need, which can create unwanted side effects.

According to the Centers for Disease Control and Prevention, about 61.9 million adults in the US are taking blood pressure medication.

“One of my hopes is that this will help inform patients how to do this themselves and also show their healthcare providers the right way,” Brady told NBC News. “Patients need to be empowered to make sure their blood pressure reading is accurate.”

The American Heart Association’s recommended position for an accurate blood pressure measurement is feet flat on the floor, back supported with arms resting on a surface and cuffs placed at mid-heart level.

The organization also urges patients to avoid smoking, caffeine and exercise within 30 minutes before the test.

Normal blood pressure is defined as less than 120 systolic and less than 80 diastolic.

Stage 1 high blood pressure is when systolic is 130 to 139 or diastolic is 80 to 89. Stage 2 hypertension is systolic blood pressure of 140 or higher and a diastolic pressure of 90 or higher.

A few points can make all the difference in a diagnosis.

And the type of cuff used to measure blood pressure can be just as important as the positioning of the arm.

A separate study published last year found that standard or “regular” blood pressure cuffs give “surprisingly inaccurate” readings for patients who require a different size — especially those who need larger cuffs.

Using handcuffs that best fit the person’s arm is recommended, but experts found that medical professionals most often use medium-sized handcuffs. These are usually the only size offered for home blood pressure monitors.

For those who find their blood pressure is too high, experts suggest exercising regularly, eating a nutritious diet, maintaining a healthy weight and quitting smoking.