Your Doctor Sees Your Blood Pressure Once a Year. Your Arteries See It Every Minute.

The office reading problem

Some people read higher at the office than at home, a pattern doctors call the white-coat effect. Others read normal at the office and higher the rest of the time, which is easier to miss and arguably more important to catch. A single office reading cannot tell those apart.

Home readings predict more

A 2012 review in the Journal of Hypertension combined eight studies that followed nearly 18,000 people over years. Home blood pressure predicted future heart and stroke events, and it held up even after accounting for office readings. Your living room, it turns out, is a better clinic than the clinic.

How to do it properly

Use an upper-arm cuff that has been validated for accuracy. The independent U.S. list is at validatebp.org. Wrist and finger devices are less reliable.

Sit quietly for five minutes first, back supported, feet flat, arm resting on a table at heart height, with the cuff on bare skin. No coffee, exercise or smoking for 30 minutes before. Take two readings a minute apart, morning and evening, for a week, and write them all down.

Bring the log to your next appointment. A week of numbers gives your doctor far more to work with than one reading on the day.

Then use the number

Average your week of readings and enter that average in your Body By Numbers report. A grade built on a real average is a grade you can trust, and the next week of readings will show you whether the changes you are making are working.