Last week we talked about cardiovascular diseases (CVDs) prevention, risk factors, and treatments. High blood pressure is one of the most important risk factors of CVDs. Studies have shown that high BP is an important risk factor for heart failure, atrial fibrillation, chronic kidney disease, heart valve diseases, aortic syndromes, and dementia, in addition to coronary heart disease and stroke. In fact, the American Heart Association states “high blood pressure (BP) is associated with the strongest evidence for causation [of CVDs]”. It’s important to know what impacts blood pressure and how to measure it- we’ll explore both today.
What is blood pressure and what does it measure?
You’re not alone if anytime you have your blood pressure measured, you aren’t really clear what the results mean. Blood pressure is the pressure of blood pushing against the walls of your arteries. Arteries carry blood from your heart to other parts of your body.
The CDC shares:
Blood pressure is measured using two numbers.
The first number, called systolic blood pressure, measures the pressure in your arteries when your heart beats.
The second number, called diastolic blood pressure, measures the pressure in your arteries when your heart rests between beats.
If the measurement reads 120 systolic and 80 diastolic, you would say, “120 over 80,” or write, “120/80 mmHg.”
A normal blood pressure level is less than 120/80 mmHg. Blood pressure changes throughout the day, and is impacted by activities you do, whether you’re sleeping (and if you have sleep apnea, that can increase blood pressure), foods you eat (check out these heart-healthy recipes!), smoking, and stress or anxiety, among many other factors. It can be helpful to monitor your blood pressure through the day to pick up on patterns and keep you aware of what impacts your BP.
Are watch and wrist monitors effective at measuring BP?
There are so many popular gadgets available to help measure heart rate, keep track of daily steps, and even measure blood pressure. Most are worn on the wrist, like the Apple Watch, Fitbit, and others. There are also some devices that are made specifically to measure blood pressure like the Everlast smart watch and the Biometric monitor. The market for tools to measure BP is ripe for an accurate device, as surveys have found that only 62% of Americans with high blood pressure only measure it a few times a month – far below the twice a day recommendation for this patient group. More than three-quarters of respondents to the same surveys said they would measure their blood pressure “more or much more” often if it was possible to accurately measure it passively in the background. Tools that are easy to use and are accurate could help patients better manage their health, with the peace of mind that the results they’re seeing are comparable to those in a provider’s office.
Studies have shown that tools like the Fitbit and Biometric monitor, among most others, are not accurate in measuring BP. Consequently, the American Heart Association recommends using a home blood pressure monitor that measures blood pressure in your upper arm and not using wrist or finger blood pressure monitors. This is partially due to how sensitive monitors are to body position. To get an accurate reading with a wrist monitor, the monitor, your wrist, and arm must be at heart level. But studies have shown that even doing this exactly as directed often still results in BP readings higher than measurements taken at the upper arm. That’s because the wrist arteries are narrower and not as deep under your skin as those of the upper arm.
But, that doesn’t mean that you have to head to a providers office or purchase a medical-grade device to measure your blood pressure at home. Using a clinically validated device can provide accurate results at home. What is clinically validated? It means the device has been tested and has shown to provide consistent, accurate results as measured by strict guidelines set by the American Medical Association, and assessed by independent review committees comprised of experts in cardiovascular health. You can find the list of all US clinically validated devices, here.
Still, it’s not uncommon for blood pressure readings taken at home on any type of monitor to be slightly different from those taken at your doctor’s office. For this reason, it’s important to take your device to your providers office to have your blood pressure checked on a standard upper arm monitor and compared to your at-home device to check the accuracy. Follow all instructions that come with the device to ensure optimal performance.
How do you use a blood pressure monitor?
Proper technique in using a blood pressure monitor is just as important as using a validated device. Use these three guidelines to provide the best results, regardless of whether you choose a wrist or upper arm monitor (but still make sure it’s a validated device!):
- Be consistent – That means same time of day and, if possible, same location. If not, make sure you’re seated in a similar chair with your arm rested at the same height.
- Stay still – For 30 minutes prior be sure to avoid exercise, caffeine, and smoking.
- Cross your heart – As in keep the cuff directly across from your heart. With a wrist monitor, that means resting your elbow on a table and holding your wrist out and up at the same level as your heart for an accurate reading.
It’s important to speak to your provider about your individual risk level and what can be done to manage your blood pressure. Coordinate a time to bring in your validated device and get familiar with it at your providers office, that way you can ask any questions with it in front of you. Self- measuring is not a substitute for seeing your provider, but can help you stay in tune with your body. Staying aware of your blood pressure is one easy way to know if you are experiencing any changes that could point to early signs of cardiovascular diseases.