Ambulatory Blood Pressure Monitoring | MedStar Health

Measuring your blood pressure over a 24-hour period

If your doctor wants a better representation of your blood pressure than can be seen in their office, they may ask you to wear an ambulatory blood pressure monitor. This device will measure your blood pressure during your normal routine at regular intervals, usually every 15 to 30 minutes during the day and every 30 to 60 minutes at night.

Readings may be used to:

  • Analyze what happens to your blood pressure as you sleep

  • Detect “white coat hypertension,” which occurs when blood pressure readings consistently are higher in a doctor’s office than when outside the office

  • Determine whether blood pressure medication is working

  • Evaluate borderline high blood pressure 

Close up photo of an ambulatory blood pressure monitor on a woman in her home.

What to expect during ambulatory blood pressure monitoring

You’ll be fitted at your doctor’s office with an ambulatory blood pressure monitor, which consists of a cuff worn around your upper arm and a small digital machine you can wear on a belt around your waist. The device works just like at the doctor’s office. The cuff will inflate around your upper arm and then slowly release the pressure. The machine stores the readings, which will be downloaded when you return it at the end of the 24-hour period.

To get the most accurate results, you’ll be encouraged to go about your daily activities as usual. The only things you should avoid are swimming and taking a bath or shower. You’ll also be asked to keep a diary of your activities so your doctor knows what you were doing when.

Some people find ambulatory blood pressure monitoring uncomfortable or distracting, particularly while sleeping. Your arm may feel a little sore from the frequent checks, and some people get a rash, which usually goes away on its own.

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