They’re up in arms!
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 blood pressure readings of 133 adults who held their arms in three different positions: resting on the lap, leaning on a surface and hanging by their side. They found that certain placements corresponded to a drastic increase in systolic pressure.
Systolic measures pressure in the arteries when your heart beats — it’s represented by the first and higher number in a blood pressure reading.
The research team found that when participants had their arms hanging by their side, their systolic pressure was 6.5 points higher and their diastolic pressure was 4.4 points higher.
Diastolic pressure, the pressure in the arteries between heartbeats, is the bottom number in the reading.
Lap support overestimated systolic pressure by 3.9 points and diastolic pressure by 4 points.
Dr. Tammy Brady — a pediatrician epidemiologist and medical director of the pediatric hypertension program at the Johns Hopkins Children’s Center — was surprised by her findings.
She noted that blood pressure discrepancies can result in the misdiagnosis of hypertension and patients being prescribed medication they do not need, which can create unwanted side effects.
According to the Centers for Disease Control and Prevention, an estimated 61.9 million US adults are on blood pressure medication.
“One of my hopes is that this will help inform patients as to how to do this on their own and also to tell their health care provider the right way,” Brady told NBC News. “Patients should be empowered to make sure the blood pressure measurement is accurate.”
The American Heart Association‘s recommended position for an accurate blood pressure reading is feet flat on the floor, back supported with arms leaning on a surface and cuff positioned at mid-heart level.
The organization also urges patients to avoid tobacco, caffeine and exercise within 30 minutes before testing.
Normal blood pressure is defined as less than 120 systolic pressure 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 couple of points could make all the difference in a diagnosis.
And the type of cuff used to measure blood pressure may be just as important as arm positioning.
Separate research published last year found that standard, or “regular,” blood pressure cuffs deliver “strikingly inaccurate” readings for patients who require a different size — particularly for those who need larger cuffs.
It’s recommended to use a cuff that best fits the person’s arm, but experts found that medical professionals most often use medium-sized cuffs. These are typically the only size provided for at-home blood pressure monitors.
For those who find out their blood pressure is too high, experts suggest exercising regularly, consuming a nourishing diet, maintaining a healthy weight and quitting smoking.
