People’s Pharmacy: Has your blood pressure been measured correctly?

If you have been to see a health care provider recently, you are familiar with the ritual of blood pressure measurement. Before you can talk with the professional you came to consult, the office will collect some data on you. First, of course, they ascertain how the bill will be paid. Then they measure your weight, your temperature and your blood pressure as a preliminary to your visit.

Why do we consider this a ritual? If it were done carefully, measuring blood pressure could provide important information about your health. All too often, though, it is treated as a necessary hoop for you to jump through rather than as a source of critical data.

How should blood pressure be measured? First, the cuff should be the correct size for the arm. Using a cuff that is too small can falsely elevate the reading, while a cuff that is too large may underestimate blood pressure. The patient should be seated in a chair with back support and feet on the floor. There should be a support for the arm at approximately heart height. Sometimes the person taking the measurement holds the patient’s arm, but ideally, there would be an adjustable arm rest or a nearby desk or table.

We did not make these recommendations up. They are described in a study published in JAMA Internal Medicine (Dec. 1, 2024). The authors note that “commonly used arm positions (lap or side) resulted in substantial overestimation of BP readings and may lead to misdiagnosis and overestimation of hypertension.”

What’s the harm, you wonder. Well, if you were misdiagnosed as having high blood pressure, you might end up on a medication you don’t need that could cause side effects. On the other hand, if you have elevated blood pressure that goes unrecognized and untreated, it could increase your chance of a heart attack or stroke. When low blood pressure isn’t identified and addressed, patients have a greater likelihood of serious heart failure outcomes (Annals of Medicine, December 2025).

Our readers have been alarmed by the technique they have witnessed during visits. Diane said: “I just had my BP taken last week at a gynecologist’s office. It seemed the nurse just wanted to get a number to enter into her laptop.

“I mentioned that I should sit still for a few minutes first and my arm should be at heart level, and she replied no, her method would be more accurate. Guess I was lucky she let me sit in a chair! Health care workers often take my BP on a sleeved arm unless I happen to be wearing a short-sleeved shirt. They don’t think there’s a difference.”

Diane is correct that sitting quietly for a few minutes and not talking while blood pressure is measured are important and have an impact on the numbers obtained. The cuff should be on bare skin, rather than clothing.

Jeanni observed: “I have white coat syndrome, so my blood pressure is always higher at a doctor’s office than when I take it at home. Before an appointment, I take my blood pressure for three days, write the readings down and show them to the nurse or doctor. So many factors can drive up your blood pressure that it makes sense to do your own blood pressure reading at home.”

We agree with Jeanni that you should track your blood pressure at home. Make sure you do it correctly!

In their column, Joe and Teresa Graedon answer letters from readers. Write to them in care of King Features, 300 W. 57th Street, 41st Floor, New York, NY 10019, or email them via their website: www.PeoplesPharmacy.com. Their newest book is “Top Screwups Doctors Make and How to Avoid Them.”