Your blood pressure offers an important glimpse into your health, but you could get even more clues by making a small change when you get it checked.
Ask to have your blood pressure taken in both arms, not just one. It’s standard procedure in cardiologists’ offices, but not a usual practice in primary care.
Healthy people can have slightly different numbers between arms, but a substantial difference in the readings could signal a blockage or an abnormality, said Dr. Sharonne Hayes, director of the Women's Heart Clinic at the Mayo Clinic in Rochester, Minnesota.
“Probably the biggest thing I see in day-to-day practice is somebody who always gets their blood pressure checked in a given arm and they’re told over and over again it’s great,” Hayes told TODAY. But when her office checks the other arm, it reveals uncontrolled high blood pressure that has gone undetected, which can potentially damage the brain and kidneys.
What to look for
Optimal blood pressure is less than 120/80 mm Hg. In addition to reaching that goal, you want the difference in systolic blood pressure — the upper number of the reading — between your arms to be within 5 points.
If it’s greater than 10 or 15 points, the first step is to recheck because you may have simply settled down and lowered your blood pressure between arm readings. If the difference persists, it should be investigated. It's all about your body's plumbing and blood flow.
In a young person, the big difference could signal a congenital heart defect called coarctation of the aorta, or a narrowing of your main artery. In an older person or somebody who is at risk for atherosclerosis, it could indicate a blockage. It could also be a potential sign of aortic dissection, a tear in the wall of the aorta.
Typically, if one arm registers higher, then that arm should be used for future measurements, whether at the doctor’s office or if you monitor your blood pressure at home, Hayes said.
How often to check both arms
The average 30- or 40-year-old doesn’t necessarily need their blood pressure checked in both arms every time they go to the doctor, she added. Get it done at least once every once in a while: perhaps initially in your teens or 20s, and then again in your 40s or 50s.
It’s more likely that a woman might have a reason not to be checking blood pressure in both arms. Breast cancer patients who have had a mastectomy and lymph nodes removed are often advised not to have their blood pressure taken in the arm on the side of the mastectomy, Hayes noted. That’s not as important anymore with modern surgical techniques, she added.