How to check blood pressure with apple watch

Steven John

Freelance Writer

Steven John is a freelance writer living near New York City by way of 12 years in Los Angeles, four in Boston, and the first 18 near DC. When not writing or spending time with his wife and kids, he can occasionally be found climbing mountains. His writing is spread across the web, and his books can be found at www.stevenjohnbooks.com.

How do blood pressure monitors actually work?

Blood pressure Apple Watch is a popular search topic on the internet. Lots of people are trying to find a watch with blood pressure monitor. Before we dive into this topic, let’s review how blood pressure monitors actually work. To measure blood pressure it requires only a stethoscope and an inflatable arm cuff hooked up to a manometer.

The arm cuff is pumped with air, cutting off the circulation in the so called brachial artery, and the pressure is then released gradually. This method was originally developed by an Italian doctor Scipione Riva-Rocci. Once the blood pressure drops below the systolic blood pressure level, the blood flow through the artery will return. However, the blood flow will be turbulent for as long as the artery remains partially compressed. This results in a pulsating noise, known as Korotkoff sound, which can be recognized by placing a stethoscope on the brachial artery. The pulsating noise disappears as soon as compression of the artery is released completely. The cuff pressure as measured at this point corresponds to the diastolic blood pressure.

This manual technique of checking blood pressure is widely replaced these days by automatic blood pressure monitoring devices. The automatic devices work on the same principle. The turbulent blood flow causes vibrations of the artery wall. These vibrations are detected by the sensors in the arm cuff. Hence automatic blood pressure monitors replace the guesswork with a no-brainer approach and produce accurate results without a need to use a stethoscope.

Are wrist based blood pressure monitors accurate?

Even if you do not have a blood pressure health challenge, you most likely had your blood pressure measured at least once in your life with an inflatable cuff at the upper arm. Most likely you also have seen different wrist based blood pressure monitors. Some of them are bigger than others and I am sure you have a question in your mind: how accurate are they compared to upper arm calf monitors? How does blood pressure watch work?

Though some of these wrist based monitors are approved by health device certification organizations and can produce reasonable results, the AMERICAN HEART ASSOCIATION still recommends using upper arm blood pressure monitors. Here is why:

• Wrist based blood pressure monitors are very sensitive to body position. Your arm and wrist must be at heart level.

• Blood pressure readings taken at the wrist are usually higher and less accurate than those taken at your upper arm. The reason for this is that the wrist arteries are narrower.

Does it mean that blood pressure in watch has no practical use?

Some people can't have their blood pressure readings taken at the upper arm because they have a very large arm. In these cases, measuring blood pressure at the wrist is acceptable. You need to take your wrist based monitor to your doctor to check for accuracy and correct body position when taking a blood pressure reading.

Scientists explore another method for blood pressure measurement: cuffless wave velocity blood pressure measurement or blood pressure wave propagation. Some experimental models produce reasonable results in lab testing. However calibration of these devices is notoriously difficult so currently none of them have been approved for medical purpose.

These are the main reasons why blood pressure monitoring watch have not become popular.

What heart health indicators can you measure with the Apple Watch?

Apple Watch is a great device when it comes to helping maintain and improve your heart health. At the time of writing this post (June 2022) the latest model available on the market is Apple Watch Series 7. Here are the main heart related features of this model:

• It measures resting and exercise heart rate and notifies you when reaching pre-set levels. It is a sophisticated heart rate monitor providing a lot of data about your pulse.

• Apple Watch Series 7 detects and alerts you to irregular heart rhythm (known as arrhythmias) so you could discuss heart health risks with your doctor. One of these conditions is called Atrial Fibrillation, or AFib. According to the American Centers for Disease Control and Prevention, 2% of people below 65 years old and 9% of people 65 and older develop AFib

• It is an ECG on your wrist. Apple Watch Series 7 can generate an ECG similar to a single-lead cardiogram.

• It measures blood oxygen. Apple Watch Series 7 includes an advanced sensor which measures a blood oxygen level, an important indicator of overall health.

But can you measure blood pressure on Apple Watch? Read on, we are almost there.

What you should look for in blood pressure apps for Apple Watch

Why do you need to choose a blood pressure app wisely? Scientific research shows that people who track their blood pressure regularly demonstrate better recovery rates for treating hypertension. For sure, you can note your blood pressure changes with pen and paper but it is much more convenient to do this with a mobile blood pressure log. There are plenty of such apps on the market to choose from. Here are the key features which you should look for in a mobile blood pressure diary app:

• Easy way to enter and annotate blood pressure readings.

• Comprehensive graphs which make it easy to understand blood pressure changes over different periods of time. Also what activities had an impact on your blood pressure.

• Ability to pull data from your Apple Health or Google Fit accounts. Most modern blood pressure monitors with Bluetooth can connect to Apple Health or Google fit. The data entry becomes automatic and you do not have to fiddle with entering BP readings manually.

• Ability to print out blood pressure checker reports or share data remotely with your doctor. Doctors love to review your blood pressure history as it helps them to adjust treatment plans.

One of the well established blood pressure apps on the market with excellent user feedback is SmartBP. This app has all the key features mentioned above.

If you are looking for an app which includes all the blood pressure tracker features above and in addition helps you to lower blood pressure without medications, you may consider BreathNow. This app helps users to lower blood pressure with calming activities like slow breathing, meditation and more and also provides useful insights re which activities help most.

IMPORTANT. There is one feature which you should NOT try to find in a blood pressure app. That is to measure blood pressure WITHOUT an EXTERNAL blood pressure monitor. The current mobile phone technology simply does not provide such functionality, at least for now.

Many apps are doing their best to lure users with promises like ‘blood pressure checker’ but once you install them and read the small print, you figure out very quickly that taking blood pressure with a phone app without an external blood pressure monitor is simply not possible for now.

Finally, back to blood pressure in watch. Unfortunately as of June 2022 you cannot measure blood press with Apple Watch. Though there are some wrist based blood pressure watches on the market they look more like a traditional wrist based blood pressure monitor than an elegant smartwatch. Plus as explained above their accuracy is a borderline case.

Can you use an Apple Watch to lower blood pressure?

If you cannot measure blood pressure on Apple Watch can you actually use it to address your hypertension? The answer is a definitive YES.

Multiple apps in the Apple Appstore allow you to enter BP readings from external monitors manually with the help of Apple Watch. Or pull out the BP data from Apple Health.

The question is, why would you want to fiddle with a small screen and inconvenient keyboard to do this if you need to use an external blood pressure monitor to measure BP anyway?

There is a much more useful function of Apple Watch when it comes to dealing with high blood pressure. That is to display slow breathing exercises to lower blood pressure. Small screen and gentle vibration allow us to perform these calming breathing exercises discreetly, without inviting much attention.

You can do these exercises even during business meetings when you need to bring down anxiety and stress without anyone noticing it.

Check out free breathing exercises on Apple Watch from the BreathNow blood pressure app. There is even a breathing exercise which will help you to fall asleep faster. No need to look at the phone or blood pressure watch: gentle vibration will guide your breathing and the Apple Watch will go into a sleep mode after you do.

Summary

Though you can’t measure blood pressure with Apple Watch (at least as of June 2027), it is a very useful device when it comes to improving heart health. Also none of the existing mobile apps allow you to measure blood pressure WITHOUT EXTERNAL blood pressure monitors. Tracking blood pressure changes and factors which impact it is CRITICAL for treating hypertension. There are multiple apps which allow you to do this including displaying blood pressure on Apple Watch. Some apps, i.e. BreathNow, go one step further and help you lower blood pressure with slow breathing exercises on Apple Watch.