By Paul M. Dake, M.D.
Q: I keep track of my blood pressure at home, but when I see my doctor, it always seems higher than my home measurements. What might be causing this difference?
A: Most people monitoring their own BP measure it while sitting on a chair with their arm up on a table in front of them; this is actually the correct position for such a measurement.
In the doctor’s office, the Medical Assistant is often in a hurry to stay ahead of the doctor and makes several mistakes when measuring your blood pressure, such as asking you to sit up on the exam table to take your vital signs as soon as you enter the exam room, applying the BP cuff over clothing (even if it’s only a light shirt), asking you questions about your reason for seeing the doctor as she takes your BP, using whichever BP cuff she first pulls out of the drawer, and sometimes even using a wrist cuff.
Every one of these aspects of BP measurement can raise the resulting value, from 10 to 50 points. An accurate BP measurement depends on the upper arm cuff being the correct size (at least 5, and preferably 6, inches wide), applied directly to skin from just above the elbow upward, after 5 minutes of sitting quietly in a chair with feet flat on the floor, and while not interacting with anyone else. Also, don’t forget about ‘white-coat hypertension’, a very real entity, and the role of stress of any sort in acutely elevating the BP. Retaking the BP at the end of the office visit and averaging this and the first BP taken in the office gives a more accurate figure.
In addition, before any person receives a diagnosis of chronic hypertension, several weeks of home BP monitoring to confirm it are usually required.
To learn more about this and many other health topics, visit the American Academy of Family Physicians’ website ‘familydoctor.org’, where you can click on the ‘Search’ box in the upper right corner of the website, and enter your topic of interest.
I want to thank Chad B. for suggesting this topic; if you have any particular topic you would like to hear more about, please message me at firstname.lastname@example.org.