If you're being treated with medication for hypertension, or being followed for borderline high blood pressure, it's imperative to keep track of trends in your blood pressure. Your doctors need to know this information when deciding whether or not to start you on medication to reduce your blood pressure, or if you're already on medication, to see whether it's working or if the dose needs adjustment.
Now, more than ever, patients are tasked with periodically checking their own blood pressure at home. And with telehealth on the rise, you may be asked to take part in self-blood pressure monitoring between virtual or in-person health care visits.
"People spend well over 98% or 99% of their time at home and just a very small period of time when they go to the doctor's office," says Dr. Sharon Reimold, vice chair of internal medicine and a professor of medicine at UT Southwestern Medical Center in Dallas. "When you go to the doctor's office, people are often rushing around, trying to get checked in on time and they're worried about what the physician or provider is going to say – that may be associated with an elevated blood pressure."
Monitoring blood pressure in the familiar environment of home makes sense. "You get a better idea of what home control is, a better idea of how to adjust medication if needed and the patient also has the opportunity to help take care of their own health in a really important way," Reimold says.
Despite pandemic disruptions, it's essential to maintain your health care. "Many people are still afraid to come into the doctor, so we do a lot of telemedicine visits," says Dr. Anjali Mahoney, an associate professor of family medicine with Keck Medicine of USC, the University of Southern California. "We are actually managing a lot of blood pressure from home. It's important that patients know what their blood pressure is and that they know how to take it properly."
Self-monitoring reflects what's actually happening with your overall blood pressure control, Mahoney notes. "There are a few studies that show that home blood pressure monitoring is more accurate than in-office, just because of white coat hypertension and things like that," she says. Here's how blood pressure readings may vary by setting:
By giving a more complete picture of a patient's blood pressure trends, "self-measured BP monitoring has high potential for improving the diagnosis and management of hypertension in the United States," according to a joint policy statement from the American Heart Association and American Medical Association, published in June 2020.
The technical term for a traditional blood pressure monitor is a sphygmomanometer. These devices consist of the inflatable cuff that goes around your arm, and the blood pressure gauge to measure the blood flow through the brachial artery – the major artery in your upper arm.
While taking a reading with a sphygmomanometer, clinicians typically place a stethoscope in the bend of your elbow to hear pounding sounds beginning and ending. The beginning sound represents your systolic (top number), and the end of the pounding represents your diastolic (bottom number) in blood pressure readings. Systolic blood pressure measures the force of your heartbeat on the walls of your arteries. Diastolic blood pressure measures the reduced force on the arteries when your heart relaxes.
By contrast, digital monitors automatically provide your blood pressure reading at the touch of a button. No stethoscope is needed, making it possible for you to monitor blood pressure independently. However, digital monitors may be less accurate than those used by health professionals. So, it's important to pick a good at-home blood pressure monitoring device.
Here's some guidance to help you choose the right device
With your blood pressure monitor handy, you're ready to go. Follow these tips for the most accurate at-home readings:
When self-checking your blood pressure, keep these timing tips in mind:
Get into a routine for each sitting. "You should take three blood pressure checks," Reimold says. "If you're anxious about it, you generally do three in a row, and you can accept the last one or average the second and third one. That just gets rid of some of the concern that a lot of patients have about how high their blood pressure is."
Consider time of day. "Blood pressure is the highest in the morning," Reimold says. "Some people also take their blood pressure medicine in the morning, and if they record their blood pressure before (having) their medicine, then it may be high." Instead, "I ask them generally to pick one or two times – sometime in the evening or maybe later in the morning – and monitor it at those times."
Don't overdo. "One thing I've seen a lot of people do: They have a high reading and they start freaking out," Mahoney says. "They just keep taking it, even in the middle of the night." That's not a good idea, Reimold concurs. "I ask people not to get into the business of taking your blood pressure 20 or 30 times a day," Reimold says. "If you do that, you may be really worried about your blood pressure and that can actually make (it) higher."
Follow your doctor's recommendations on frequency. "Once I have someone whose blood pressure is under excellent control, I think probably just checking their blood pressure once a month or so is useful," Reimold says. "On the other end of that, if I am starting therapy or I'm adjusting therapy, I may ask them to do it one to two times a day, every day." After a week or two, patients provide her with this data to help inform treatment decision-making.
Although the main reason for self-monitoring at home is to provide more information to track blood pressure trends, an individual result can sometimes raise a red flag for a possible emergency or at the least be cause for concern. Here's when to contact your doctor:
If you're healthy and have never had a problem with high blood pressure, you don't necessarily have to invest in a home monitor. However, adults 18 and older should be medically screened for high blood pressure, at intervals depending on the factors below, according to the U.S. Preventive Services Task Force, an influential health panel of independent medical experts.