You might assume that only doctors and nurses would have blood pressure equipment lying around the house. But blood pressure monitors may become more commonplace now that updated American Heart Association guidelines emphasize the value of taking blood pressure at home.
"We now have good evidence about the usefulness of home blood pressure monitoring," says co-author Daniel W. Jones, MD, a spokesperson for the American Heart Association (AHA) and the dean of the School of Medicine at the University of Mississippi Medical School. "This is an add-on to office measurement, so home monitoring is not replacing office measurement."
The guidelines, published in February in the journal Circulation, suggest that home monitoring, including 24-hour ambulatory monitoring where someone wears a device that takes blood pressure about every 20 minutes, can help doctors better assess people's risk for heart attack and other cardiovascular problems by detecting "white coat hypertension."
People with white-coat hypertension have high blood pressure readings in the doctor's office because they experience stress in the office setting that raises their heart rate and blood pressure, but do not necessarily have hypertension, which is blood pressure that stays elevated over a period of time. For people who tense up when a doctor or nurse tells them to roll up their sleeve, home monitoring may help determine if they truly need blood pressure medication, and if so, what dose is appropriate.
Ambulatory monitoring offers extra information about hypertension because it demonstrates how your blood pressure and heart rate respond to exercise, sleeping, lying down and standing up, and other changes.
According to Dr. Jones, people with hypertension should consult with their doctors about whether they should monitor their blood pressure at home. If blood pressure monitoring is recommended, people need to know how often they should monitor their blood pressure and with what type of equipment.
You might be familiar with blood pressure monitors in medical practices, where a column of mercury rises in a glass tube, though these devices are starting to be replaced because of environmental concerns about mercury. But the two types of equipment generally recommended for home measurement are aneroid and digital monitors. The manual aneroid monitor has a circular gauge with a pointer and an arm cuff that is inflated with a rubber bulb, as well as a built-in stethoscope so you can hear your heartbeat. The digital monitor shows an electronic reading on a small screen and comes with a cuff that automatically inflates to fit your arm when you push a button. Since the machine registers the heartbeats, there is no attached listening device.
"The more automated the system you use to measure blood pressure, the more likely you'll have an error with the instrument," Dr. Jones says. "The less automated the system, the more likely you are to have a human error."
When choosing an instrument, you'll need to consider your hearing, which needs to be sharp to use the aneroid monitor, and your vision, as you need to be able to see the readings clearly. The AHA guidelines warn that cuff size is also important. If a cuff is too large, it may make your blood pressure seem lower than it is, and if it's too small, your blood pressure readings may skew high. While a cuff should fit snugly on the upper part of your bare arm, you should be able to put a finger under the cuff. It's a good idea to bring your monitor to the doctor's office to have its fit and accuracy checked.
According to Dr. Jones, your doctor should also let you know what blood pressure levels are normal for you, and what you should do if your levels are out of range. These steps will vary from person to person based on their age and state of health.
Although it may seem like a hassle, home blood pressure monitoring can help you and your doctor gain a thorough understanding of your everyday blood pressure fluctuations, and therefore your heart disease risk, so be prepared to start playing doctor at home.
"Accurate measurement is important and all of these methodologies—office, home and ambulatory—are important for determining blood pressure," Dr. Jones says. "Patients with high blood pressure should work with their health professionals to devise a plan that's best for them."