Digital wrist and arm cuff monitors, which I prefer over the manual devices that you pump by hand and that usually require a stethoscope, work in essentially the same way. Both consist of a cuff and a gauge that reads your blood pressure. At the touch of a button, the cuff automatically inflates, and the device then calculates your heart rate and your blood pressure by measuring blood flow. The cuff deflates automatically after the reading is taken.
I generally recommend an arm cuff monitor over the wrist monitor or finger monitor because I’ve found its readings to be more accurate. (Standard cuffs fit an arm from 8.6 to 12.6 inches in circumference, although smaller or larger cuffs are available.)
To make sure a home blood pressure device is working properly, I ask my patients to bring their equipment into my office periodically to compare the readings I get to the ones they are getting at home. In general, I’ve found that the more high tech the device (some come with enhanced memory and electronic printout capability), the more errors it tends to make. Whatever model you buy, be sure to follow the directions that come with it. Most devices, for instance, recommend relaxing for a minute or two after taking a reading and then doing a repeat reading to check for accuracy. It’s a good idea to keep a manual log of your readings, although some machines will do this for you.
Keep in mind that blood pressure tends to vary throughout the day and is often a little higher first thing in the morning. Wait an hour or so after awaking and avoid food, caffeine, cigarettes, or alcohol 30 minutes before taking a measurement.
Blood pressure is also usually higher when you are in pain, have a headache, or are generally not feeling well. And it is typically high both during and right after exercise as well. If a couple of readings are higher than usual, don’t panic: It’s the pattern of your readings over time that’s important.
