Blood pressure: Can it be higher in one arm?

When I measure my blood pressure at home, I've noticed that the reading is always higher in one arm. Should I be concerned?

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Mayo Clinic hypertension specialist Sheldon Sheps, M.D., and colleagues answer select questions from readers.

Answer

It depends. A small difference in blood pressure readings between your arms is generally not a health concern. Sometimes blood pressure is higher in your dominant arm. For example, if you're left-handed, your left arm may have a higher reading than your right arm. This difference is usually less than 5 millimeters of mercury (mm Hg).

A difference of more than 10 mm Hg in one arm may be a sign of an underlying problem — such as narrowing of the main arteries to that arm — and should be evaluated by your doctor.

Many factors affect blood pressure. To detect a difference in blood pressure between your arms, your doctor may take a series of alternate-arm blood pressure readings. He or she may also measure your blood pressure in both arms at the same time with two blood pressure gauges and two observers.

If your blood pressure is higher in one arm, your doctor will usually use the blood pressure reading from that arm to monitor your blood pressure.