A blood pressure reading in the office is one moment on one day. Readings at home, taken the same way over weeks, show what your blood pressure does in ordinary life. For many people they are the most useful numbers a doctor sees.

Getting good numbers depends mostly on technique. This guide follows the American Heart Association’s advice. It is general information; your own targets and how often to measure are questions for your doctor.

Who benefits from home monitoring

The American Heart Association recommends home monitoring for everyone with high blood pressure, to help their healthcare professional know whether treatment is working. AHA notes it can also help confirm a diagnosis, and that it matters most for people starting or changing treatment and for people who need closer monitoring.

AHA is equally clear that home monitoring does not replace regular doctor visits, and that you should not stop a blood pressure medicine on the basis of home readings without checking with your healthcare professional.

Choosing a monitor

AHA recommends an automatic, cuff-style monitor that goes on the upper arm. Wrist and finger monitors are not recommended because they give less reliable readings.

  • Choose a validated device. AHA points to validatebp.org, a listing of monitors that have been checked for clinical accuracy. A pharmacist can also help.
  • Check who it was validated for. AHA advises making sure a monitor is validated for older adults if that is who will use it.
  • Get the right cuff size. Measure around your upper arm and choose a monitor with a cuff that fits. AHA notes that the wrong cuff size gives inaccurate readings.

Once you have a monitor, take it to your next appointment so your doctor can compare it with the office equipment and watch you use it. AHA suggests bringing it in about once a year, or as the manufacturer directs, to confirm it is still accurate.

Step by step: taking a reading

  1. Plan ahead. Avoid smoking, caffeinated drinks and exercise for 30 minutes before. Empty your bladder.
  2. Bare the arm. Do not measure over clothing. AHA notes that either arm can be used, since there is usually not a big difference between them.
  3. Support the arm. Rest your arm on a flat surface so the middle of the cuff is at heart level, with a pillow under the arm if needed.
  4. Place the cuff. The bottom edge should sit just above the bend of the elbow, on bare skin.
  5. Rest quietly. Sit still for at least five minutes before measuring. Do not talk or use the phone.
  6. Take two readings. Take two readings one minute apart and write both down.
  7. Be consistent. Measure at the same times each day, and ask your doctor how often to check.

AHA offers a printable log and a one-page illustration of correct position on its home monitoring page. If your monitor stores readings, bring it to appointments.

Making sense of the numbers

AHA’s blood pressure categories define normal as a top number below 120 and a bottom number below 80. A top number of 120 to 129 with the bottom below 80 is the next category up, a signal to recheck with your healthcare team. Stage 1 high blood pressure is 130 to 139 on top or 80 to 89 on the bottom, and stage 2 is 140 or higher on top or 90 or higher on the bottom. Only a healthcare professional can confirm a diagnosis.

A single high reading is not, on its own, a cause for alarm. AHA advises measuring again and writing both results down. If readings are suddenly higher than 180/120, wait at least one minute and test again, and contact your healthcare professional right away if they stay that high. If a reading above 180/120 comes with chest pain, shortness of breath, back pain, numbness, weakness, a change in vision or difficulty speaking, AHA says to call 911.

Sharing your readings with your doctor

A log is most useful when it reaches the person adjusting treatment. Note the date, time and arm for each reading, along with anything unusual, such as a missed dose or a poor night’s sleep. Look for patterns over weeks rather than reacting to single days.

Blood pressure and kidney health are closely linked, which is one reason Dr. Shtern, who is board-certified in Internal Medicine and Nephrology, pays close attention to both. Our hypertension page describes the practice’s approach, and reading your kidney labs explains the related lab tests. Many blood pressure follow-ups work well by video visit, with your home log in hand.

If you would like to bring your monitor and meet the doctor, the first visit at Legacy Medical is a complimentary meet and greet with Dr. Shtern.

This article is general information, not advice for your situation. Members can call the office with questions about their own care.