“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.”

54 million US adults may be misdiagnosed with high BP based on bad readings. Many people may be surprised to learn the proper procedure for taking a blood pressure reading—because of how different it is from what happens during their doctor's appointments.

“Hypertension is regarded as the silent killer. There are no symptoms until there is a major event or catastrophe,” said Dr. Michael Zevitz, who is a Cardiologist at Aspirus Cardiology-Rhinelander. He says people can have high blood pressure for years and not develop any symptoms.

How your arm is positioned when you get your blood pressure checked can make a big difference in the reading, a new study says.

The researchers found that when people had their arms hanging by their sides during the reading, their systolic pressure was 6.5 points higher than when their arms were resting on a desk, while the diastolic blood pressure — the bottom number — was 4.4 points higher than in the supported condition.

A new study found that having your arm in the wrong position during blood pressure checks can result in readings 'markedly higher.'

Two common arm positions for getting a blood pressure reading can lead to misdiagnoses of hypertension, new research finds.