When monitoring your blood pressure at home, using the correct cuff size is essential for obtaining accurate readings. A study published online on August 7, 2023, by JAMA Internal Medicine found that using a "regular"-sized arm cuff with an automated device led to inaccurate blood pressure readings for people who needed a small, large, or extra-large-sized cuff.
The Consequences of Using the Wrong Cuff Size
The study revealed that using a cuff size that doesn't match your arm circumference can result in significant discrepancies in blood pressure readings:
For individuals needing a small cuff, using a regular-sized cuff produced an average systolic reading (the top number) that was 3.6 millimeters of mercury (mm Hg) lower than with an appropriately sized cuff.
For adults who needed a large cuff size, using a regular-sized cuff resulted in higher systolic readings by an average of 4.8 mm Hg.
For those requiring an extra-large cuff size, using a regular-sized cuff led to an average increase of 19.5 mm Hg in systolic readings.
Smaller discrepancies were also observed in diastolic blood pressure readings (the bottom number) for adults who had cuffs that were either too large or too small.

Choosing the Right Cuff Size for Your Arm
Most home blood pressure monitors come with a regular-sized cuff, which can accommodate arm circumferences of nine to 17 inches. However, smaller and larger cuffs are available for those who need them. To determine the right cuff size for your arm, follow these steps:
Measure your arm circumference at the midpoint between your shoulder and elbow.
Consult the cuff size chart provided by the manufacturer of your blood pressure monitor.
Choose the cuff size that corresponds to your arm circumference measurement.
If you're unsure about your cuff size or have any concerns, consult your healthcare provider for guidance. They can help you determine the appropriate cuff size and ensure that you're using your home blood pressure monitor correctly.
The Importance of Accurate Blood Pressure Monitoring
Monitoring your blood pressure at home is an important part of managing your cardiovascular health. Accurate readings can help you and your healthcare provider make informed decisions about your treatment plan and lifestyle changes. By using the correct cuff size and following proper measurement techniques, you can ensure that your home blood pressure readings are reliable and informative.
For more information on home blood pressure monitoring and cardiovascular health, visit the American Heart Association and the Centers for Disease Control and Prevention websites.