The Surprising Reason Your Next Blood Pressure Reading Could Be Way Off

When it comes to heart health, maintaining a normal blood pressure reading is key. According to the Centers for Disease Control and Prevention (CDC), your blood pressure reading measures how much pressure your blood puts on the walls of the arteries. Over time, high blood pressure can cause damage to the walls of the arteries and put you at risk for heart disease.

Our blood pressure is constantly changing throughout the day, so it's unlikely that you will get the same number on each reading. Our bodies require different amounts of blood for the various activities we perform. For example, your heart doesn't work as hard while you're dozing off on the couch as it does when you're running on a treadmill. However, your blood pressure shouldn't have significant changes from one reading to the next (via Verywell Health). If your blood pressure reading is way off, it could point to this unexpected factor.

Using the wrong cuff size causes blood pressure reading errors

You may have assumed that blood pressure cuffs are one-size-fits-all because you've only seen one size at your doctor's office. However, blood pressure cuffs come in different sizes to accommodate differences in arm circumference. Research presented during a 2022 scientific session at the American Heart Association's Epidemiology, Prevention, Lifestyle & Cardiometabolic Health Conference indicates that improper cuff size can cause major errors in blood pressure readings.

Dr. Tammy M. Brady, vice chair for clinical research in pediatrics, associate professor, and medical director of the Pediatric Hypertension Program at Johns Hopkins University in Baltimore, said, "In our study, the overestimation of blood pressure due to using a cuff that is too small misclassified 39% of participants as being hypertensive, while the underestimation of blood pressure due to using a cuff that is too large missed 22% of participants with hypertension," (per the American Heart Association).

Inaccurate blood pressure readings can lead to misdiagnosis and missed opportunities for treatment of hypertension. The next time you have your blood pressure checked, you should ask if the cuff size is the right fit for you.