>>> as we mentioned earlier, the health news has to do with a basic staple of the doctor's office, getting your blood pressure checked. if your last time at the doctor they only measured it on one arm, well, new research says they're doing it wrong. further, they say, doing it right could reveal a big health risk. our report from our chief medical editor dr. nancy snyderman.
>> reporter: doctors who measure blood pressure in only one arm may be missing critical information about their patient's heart health. a new study published in the journal "the lancet" shows the differences in blood pressure readings between both arms could point to underlying health risks. if the systolic pressure, the top number in a reading which measures the pressure in the artery where the heart beats, differs by 15 points in each arm, this study shows that a person is at 2.5 times higher risk of prefrl vas car disease, meaning blood vessels in the handed a feet are more likely to become blocked. risk of stroke is 1.6 times higher. risk from death of heart attack is 70% higher. some risk factors for hypertension are ages, genetics, age and obesity. your doctor should take blood pressure in each arm. if it's high in one arm, have that blood pressure repeated because some people develop something we call white coat hypertension. they go to their doctors, they're nervous, blood pressure goes up and settles down after a short time. brian, if that's not you and your blood pressure stays up, that's the time you go on and have further tests. it's amazing how many people have falsely elevated blood pressure and don't know it.
>> that's the effect.
>> it's that white coat.
