Why blood pressure cuffs can be wildly inaccurate: new study

The classic, one-size-fits-all blood pressure cuff being used by most doctor’s offices could be hazardous to your health, experts are warning.

A new study, published Monday in respected journal JAMA Internal Medicine, found that standard, or “regular,” blood pressure cuffs are delivering “strikingly inaccurate” readings for patients who required a different size — particularly for those who needed larger cuffs.

Accurate readings are incredibly important in diagnosing conditions such as high blood pressure, also known as hypertension — the leading cause of heart disease worldwide.

Clinical guidelines recommend using the cuff that best fits the person’s arm. However, experts found that medical professionals most often use midsize cuffs. These are typically the only size provided for at-home blood pressure monitors.


Closeup of unrecognizable man in white t-shirt using modern tonometer at home
High blood pressure, also referred to as hypertension, is the leading cause of heart disease worldwide.
Getty Images/iStockphoto

Johns Hopkins University School of Medicine researchers analyzed blood pressure readings from 195 adults with a wide range of mid-arm circumferences.

After walking around for two minutes, the participants had their blood pressure measured using three different cuff sizes in random order: the regular, standard size; an appropriate, fitted size; and a third size that was either too small or too large.

They found that those requiring a small cuff reported consistently low blood pressure readings. In contrast, those requiring a large or an extra-large cuff reported high blood pressure measurements with major errors.

The effects did not vary depending on a person’s existing blood pressure or obesity status, the study found.


person is using sphygmomanometer for check his health
The most inaccurate readings were found when a person used a blood pressure cuff that was too small or too large for them.
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“We were shocked at how big of a difference there was,” lead study author Dr. Tammy Brady told CNN. “I didn’t expect the magnitude that we found.”

In the end, the experts concluded that the traditional, one-size-fits-all approach too often yields incorrect blood pressure readings that mislead medical professionals, resulting in incorrect diagnoses and health advice.

The team advised that both patients and providers should be better educated about the importance of using the right cuff — and warned against using public blood pressure kiosks.

“It can have really significant clinical implications,” Brady said.

For those interested in lowering their blood pressure, exercise is considered to be right at the top of the list, along with a healthy diet, losing weight and quitting smoking. For a specifically heart-healthy workout plan, a recent study revealed which types of exercise might be most effective.