How Accurately Do Fitness Trackers Measure Blood Pressure? (2024)

Picture yourself out for a morning jog, the latest and greatest fitness tracker strapped to your wrist, wirelessly beaming stats to your phone and the cloud. Among the sea of data—steps taken, calories burned, heart rate—there's one number that's particularly important when it comes to monitoring your health: blood pressure.

Can your fitness tracker measure your blood pressure? If so, how much faith can you place in your wearable? In this article, we examine the accuracy, the science, and the real deal of fitness trackers measuring your blood pressure. It's time to check the pulse of your pulse-checker!

Comparing Blood Pressure Trackers

Each year, the never-ending list of fitness trackers that promise the moon and the stars continues to grow. From makers like Fitbit, Garmin, Apple, and Samsung, they all want to claim a spot on your wrist.

However, most fitness trackers are incapable of measuring blood pressure.

Methods for Measuring Blood Pressure

At their core, most generalist fitness trackers (those that aim to do many things) that measure blood pressure use light-based sensors, called photoplethysmograms (PPGs), to measure blood flow. While they offer a glimpse into your heart's rhythm and rate, getting an accurate blood pressure reading can be tricky.

Take, for instance, the Fitbit Charge 5. Rather than measuring blood pressure directly, the Charge uses its heart rate monitor combined with other metrics to give an approximation. The PPGs shine a light on the skin, which measures the blood flow and heart rate. While it provides a blood pressure reading, the estimation might not always be spot-on.

Samsung devices take a different approach. For example, the Galaxy Watch Active measures something called pulse transit time. It's the interval it takes for your heartbeat's pressure wave to travel between two points in an artery.

Using the pulse transit time method is more of a dip into the blood pressure pond, providing insights into BP trends rather than clinically reliable measurements.

This metric only gives you the BP change-up, not the exact score. You also need to set the benchmark using a traditional blood pressure device.

Similarly, Garmin's vivosmart 4 relies on PPG sensors for heart rate monitoring. While it doesn't monitor blood pressure, it uses its proprietary "Body Battery" algorithm by amalgamating data like heart rate variability (HRV), stress, and activity levels to give you a sense of your energy, but again, this isn't a blood pressure measurement.

Garmin does make a dedicated blood pressure tracker, the Index BPM Smart Blood Pressure Monitor, which employs an arm-wrap design similar to devices found in doctor's offices and pharmacies.

This device provides accurate blood pressure readings, updates metrics to the Garmin Connect app, and allows you to share reports with your doctor.

Fitness trackers, as nifty as they are, aren't typically FDA-approved or medically validated to diagnose or monitor conditions. They're great for general insights, but when precision is paramount, it's medical devices you'll want to seek.

Don't lose all hope. Your wearable can track your health accurately in many other areas.

All that said, we are starting to see some dedicated blood pressure devices that you can wear on your wrist. Take, for example, the Omron HeartGuide. It employs the oscillometric method–the same used in traditional arm cuffs.

Omron has designed the device with miniature air bladders in the watch's band that inflate and deflate to get blood pressure readings. However, this method is not nearly as accurate as blood pressure monitors affixed to the upper arm.

As a company, Apple is defined by its ability to innovate. And wellness has become a core part of Apple's business model. As such, they are investing deeply into glucose and blood pressure sensors that can be incorporated into their Apple Watch lineup. It's relatively hush-hush for now, but if anyone can shake things up, it's Apple.

Even though most mainstream wearables are not currently able to measure blood pressure directly or accurately, companies like Apple and Fitbit are working to change that.

The race to incorporate a blood pressure monitoring feature into a wearable device is in full swing, with each brand investing in technological breakthroughs. While we must wait until our wrist-based gadgets can replace the doctor's trusty blood pressure device, we can expect something more mainstream in the coming years.

In short, while your generalist fitness tracker is a phenomenal sidekick for health insights, it probably is not the best tool to diagnose hypertension.

Expert Opinions on Fitness Tracker Blood Pressure Measurements

It's natural to seek out gadgets that promise to keep tabs on our health. But when it comes to measuring blood pressure, not all fitness trackers are created equal. So, what do the pros think?

Many in the health and fitness domain raise an eyebrow at the blood pressure claims made by some fitness trackers. For instance, research published in the Journal of Human Hypertension that looked at consumer blood pressure measuring devices didn't even consider smartwatches that measure blood pressure by proxy, such as the Samsung Galaxy Watch Active.

A review by Consumer Reports suggested that the tech is promising but not quite at par with clinical devices.

Consumer Reports also states that monitors with a cuff that you wear on your wrist, such as with the Omron device, are generally not as accurate as those with a cuff that you put on your upper arm. The Heart Guide received a low score of accuracy.

Thankfully, there is a list of validated devices. This compilation includes gadgets rigorously tested for accuracy. So, if you're looking for something that accurately measures blood pressure, this is where you want to look.

In the grand scheme of things, wearables are best used as a supplementary tool, at least when it comes to measuring and monitoring blood pressure.

Everything You Need to Know About Blood Pressure Devices

Fitness trackers are barreling ahead with bold claims about things like blood pressure monitoring. And while they're making strides, being innovative, and doing what they can with existing tech and sensors, there's room to refine accuracy.

For now, if you're looking for a trusted device to measure and monitor blood pressure, you'd be wise to lean on trusted methods. After all, when your health's on the line, it's worth getting that measurement right.