Stress, exercise, and even a few drinks the night before your doctor's appointment can push your blood pressure up. So it's often difficult to tell whether an unusually high reading at the doctor's office means you have high blood pressure—or, if you have already been diagnosed with hypertension, that it's worsening— or whether a work deadline has temporarily inflated your numbers.
To offset this problem, many doctors encourage people to monitor blood pressure on their own. Home monitoring is especially useful for people with white-coat hypertension or labile hypertension, as well as to track responses to exercise, medications, or changes in treatment. It gives a more accurate idea of your blood pressure. It can help fine-tune the strategy for keeping your blood pressure in check. And it just might make you more invested in controlling a problem that has no symptoms until it spawns a heart attack or stroke or leads to heart or kidney failure.
When you first start to check your blood pressure at home, measure it early in the morning and again in the evening, every day for a week. If most of the readings fall into the goal numbers recommended by your doctor, you can check your blood pressure two or three times per week. Don't panic if one reading is high. Keep in mind that your blood pressure changes constantly throughout the day.
Many blood pressure meters store a week's worth of readings, or more. If yours doesn't, keep a record so you can show your doctor. There are some apps that will do this for you. Some even take the readings directly from the monitor, so that you don't need to write them down.
Doctors warn, however, that home blood pressure monitoring can become too much of a good thing. Just as getting on the scale several times a day is counterproductive when it comes to losing weight, overly frequent monitoring can create anxiety over small fluctuations without contributing to long-term blood pressure management.
Choosing and using a home blood pressure monitor
There are dozens of home blood pressure monitors on the market, ranging in price from about $50 to $100. For best accuracy and ease of use, buy one with a cuff for the upper arm that automatically inflates and that automatically records the pressure. Models that store readings for a week or two can simplify record keeping.
Be sure to choose one with the correct cuff size—the inflatable part should completely cover at least 80% of your bare upper arm. (If the cuff is too small, you can get a reading that is too high.) Test it in the store to be sure it's easy to use. Note that the American Heart Association doesn't recommend wrist or finger home blood pressure monitors, as they are not as reliable.