If the blood pressure measurement in your right arm is significantly different than that in your left arm, then you could be at an elevated risk of a heart attack or stroke.
British researchers analyzed 20 studies covering differences in systolic blood pressure – or the pressure exerted on blood vessels when the heart is contracting.
Their findings, published in The Lancet, showed that a difference of 15 mm Hg (millimetres of mercury) or more between arms indicates the patient is likely suffering from partly clogged and obstructed arteries.
In healthy individuals, blood pressure is normally equal on both sides of the body, said lead researcher Christopher Clark of the Peninsula College of Medicine and Dentistry at the University of Exeter.
"The blood vessels in both arms are, of course, connected to the same circulation," he said. "So there must a narrowing [in one or more places]to cause the drop in pressure."
Dr. Clark and his fellow researchers believe doctors should take blood pressure readings in both arms as part of routine medical examinations. It's a relatively simple and inexpensive method for identifying patients who may need additional evaluation. And for patients already being treated for cardiovascular disease, it could be a sign they require extra therapy.