Unmask hypertension: Track your blood pressure

Your blood-pressure checks at the doctor’s office may read normal, but that doesn’t necessarily mean you’re in the clear: Up to 20% of adults have “masked hypertension,” according to some estimates. That’s when blood pressure measurements are lower at the physician’s office than they are at home.

Experts aren’t completely certain why it happens, but scientists have recently discovered that people with this form of hidden hypertension have a 55% increased risk for heart attack or stroke, compared with those with normal blood pressure, according to a research review. The same analysis found that home blood-pressure monitoring helps identify masked hypertension.

Doctors may recommend home monitoring (in addition to regular check-ins at that office) for people diagnosed with high blood pressure, those with pre-hypertension, or even people who just have risk factors for the condition, including family history, advanced age or obesity. Left untreated, hypertension can damage your heart, arteries and kidneys and lead to stroke and vision loss, among other complications.

Keep tabs on your pressure at home; that can help doctors make an earlier diagnosis, as well as track your treatment and encourage better blood-pressure control. Talk to your physician; if home blood-pressure monitoring is suggested for you, here are some tips to help you get started:

Choose an arm monitor.

It’s more accurate and reliable than the devices that take readings from your wrist or finger. The American Heart Association (AHA) recommends this type of monitor. Measure around your bicep, and choose a monitor that comes with the correct cuff size. Digital devices are more expensive than manual ones, but they’re easier to use — they automatically inflate and deflate the cuff (instead of you having to pump), and they provide digital readings, as well as pulse rate; certain manual monitors require the use of a stethoscope.

Measure at the same time every day.

Either in the morning or at night, according to the AHA. Don’t smoke, drink caffeinated beverages or exercise 30 minutes before taking a reading. Sit in a chair, with your back straight and both feet flat on the floor and make sure your arm is supported on a flat surface at heart level. Take two or three measurements each time, one minute apart.

Track your results.

Record every reading, including the date and time; the AHA offers online and printable trackers at heart.org. You can also download apps to note your pressure, as well as your weight and other lifestyle factors. Some monitors can store your numbers; others allow you to upload readings to a website. One high reading is not a cause for concern, but if your numbers are consistently elevated, consult your doctor. If your pressure reaches a systolic (top number) of 180 mm Hg or higher or a diastolic (bottom number) of 110 mm Hg or higher, wait a few minutes and take it again, the AHA says; if it’s still at or above that level, seek emergency treatment.

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