How Does A Smartwatch Measure Blood Pressure?

For the past few years, manufacturers of smartwatches have been looking for ways to measure blood pressure at a clinical standard through their innovative watch designs, and due to technological advancement, blood pressure measurement via smartwatches is becoming more accurate and detailed. But how does a smartwatch measure blood pressure?

This is one of the questions in the minds of smartwatch users. So today’s article will share some insight on the question and other things you need to know about blood pressure measurements via smartwatches. The good news about this smart device is that you can use it to measure how well your heart pumps blood to your lungs and every other part of the body.

One of the ways smartwatches measure blood pressure is by use of an inflatable cuff which is built into the watch. Another way is through the light sensor technology which is known as PPG, and this technology is what is used to detect heart rate. Note that there are lots of sensors that can be embedded onto watches, which will give you more precise details and completely monitor and measure your overall health status any time you want.

Any health data collected from these watches can synchronize with your smartphone or tablet in real-time, which will give you detailed results and quick responses. However, be aware that no matter the brand of smartwatch you use in measuring your blood pressure, remember that blood pressure measurement results can vary depending on your current emotions, activity, and other factors. So to ensure you get an accurate readings, the following must be adhered to:

1.       You shouldn’t smoke, exercise, or drink caffeine for a minimum of 30 minutes beforehand.

2.       Make sure you use the bathroom and then rest without talking to anyone for 5 minutes before reading.

3.       Make sure your cuff is placed on your bare upper arm at heart level.

4.       Make sure that you’re seated on a sturdy chair that has a supportive back, with your cuffed arm on an armrest and ensure your feet remain flat on the floor.

What is Blood Pressure?

Blood pressure is the pressure of blood that is distributed against the walls of blood vessels. These blood pressures are due to the heart pumping blood via the body circulatory system. This is to say that the force of distributing blood to the walls of the arteries is what is called blood pressure.

Blood pressure measurements can be taken in two ways:

ü  Systolic blood pressure. This is the pressure that occurs during heart beats whenever the heart muscle squeezes and pumps oxygen-rich blood into the blood vessels.

ü  Diastolic blood pressure. This is the pressure that occurs on the blood vessels whenever the heart muscle is relaxed.

How Blood Pressure is Measured Traditionally?

The way blood pressure is measured traditionally is by tightening the cuff and sensing the pressure exerted by blood on an artery when relaxed around your arm. However, one of the most used clinical apparatus used by doctors is a manual sphygmomanometer, which is sometimes called a manual blood pressure monitor.

This apparatus contains a standard arm cuff, a rubber squeeze bulb, a reading scale, and a stethoscope. Note that we have two types of manual monitors which are mercury and aneroid.

They both use mercury sphygmomanometer in measuring blood pressure via the height of a mercury column. This method is commonly used during clinical tests and when screening someone with high-risk blood pressure.

The Importance of Accurate Blood Pressure Measurement

The accuracy of measuring blood pressure is very important if you must prevent and treat any blood pressure related illness. While administering an ill patient, blood pressure measurement accuracy is essential to monitor cardiovascular homeostasis.

One of the importance of blood pressure reading accuracy is to have a clearer understanding of the risk of having heart disease and stroke, so you can prevent it. If you get a result that tells you that your blood pressure is lower than what it is, may end up giving you a false feeling about your health status.

Technology used in smartwatches to measure Blood Pressure

how does a smartwatch measure blood pressure

The technology used in modern smartwatches to measure blood pressure is the flashing green light sensor which is used in measuring your heart rate from the smartwatch. The Spectroscopy will show you that blood absorbs the green light since red and green are opposite of each other on the color wheel.

There are two common technologies used in smartwatch’s in measuring blood pressure:



There are some watches, such as the Samsung Galaxy Watch 3, that can measure blood pressure with the use of a PPG optical sensor in taking blood pressure readings. These sensors can be found on the rear side of the smartwatch. There’s also a sensor positioned at the back of a smartwatch that helps in recording the timing and the strength of the signals that make a heartbeat. But this is for watches that use the ECG technology.

While the PPG technology makes use of a light source and a photodetector to bring out the volumetric deviation in the blood pressure that flows through the arteries.

Comparison with traditional Blood Pressure measurement methods

To compare the traditional and smartwatch’s way of blood pressure measurements, you have to understand that their methods differ. For the traditional method, a patient will have to place a stethoscope over the major artery in the upper arm and then listen to the blood flow and pulses once the cuff inflates and deflates.

When using a smartwatch, the blood pressure cuff will automatically inflate, deflate, and measure the blood pressure with the help of its sensor.

However, the intra-arterial measurement of blood pressure ( traditional) happens to be the most accurate method due to its ability to give you a continuous detailed result. While the indirect recordings (smartwatches) will give you a rough and sometimes inaccurate estimate of intra-arterial blood pressure. Though sometimes this is influenced by the information gotten about you and your environment by the smart device.

Limitations and accuracy of smartwatch Blood Pressure measurement

As mentioned above, your environment presently can affect how accurately a smartwatch will display it’s blood pressure results. Generally, blood pressure at night will be higher than that of the day. Also, it is normal for your blood pressure to rise after exercise, but it will drop slightly once you rest.

Note that the accuracy of smartwatch blood pressure measurement can also be affected by specific diets. But the way to confirm that your smartwatch’s blood pressure is accurate is when the displayed results are nearly identical.

However, there are some limitations in using smartwatches for blood pressure measurements which are:

Their sensitivity to movement.

Their results are not as precise as a sphygmomanometer.

Smartwatch Blood Pressure Measurement Features

There are watches with built-in sensors to monitor your health. These sensors can be found under the smartwatch face, against the skin of your wrist. Some smartwatches come with many features which include blood oxygen levels, workout data, a pedometer, HRV, calories consumption monitor, heart rate, sleep quality, weather checker, fitness tracker and others.

This means that whatever you want to track, it will be easy to have access to your health data by just simply tapping the screen.

Comparison of Blood Pressure measurement features across different smartwatch brands and models

Many watches come with different features when it comes to measuring blood pressure. So let’s take a look at some of the blood pressure features you can find in various smartwatch brands on the market.

The Popglory blood pressure smartwatch

This is one of the best brands of watches that is referred to as a double booster when it comes to health and fitness tracking devices. It features a heart rate and breath rate monitor, oxygen concentration, calories burner, sleep schedule, and step counting sensor. It also comes with many features found in other bands such as music control, ability to make and receive calls, find my phone, message reader, do not disturb mode, weather forecast, video streaming, and wrist sense.

The Amazfit GTS 2 Smart Watch

how does a smartwatch measure blood pressure

We can say that this is the best watch from the Amazfit brand. This watch comes with several features that are similar with other smartwatches found on the market. However, the best part of its features is having a blood pressure monitor. The blood pressure monitoring feature is what helps in measuring your blood pressure when you want to.

It also comes with a fitness tracker, weather checker, sleep monitor, heart rate tracker, and GPS tracking sensor with the ability to track your distances.

The watch is compatible with Bluetooth and this means you can do Bluetooth calling. It comes with a calendar, stress monitoring sensor, blood oxygen monitor, and features a reminder indicator. This watch provides you with the exact measurements of the blood pressure that it calculates.

The HAFURY Blood Pressure Watch

This is another ultimate health tracking watch that not only displays 24-hour heart rate readings accurately, but has the ability to track your oxygen level, check your blood pressure, stress level, sleeping time, can count your steps, calories burner, and breathing rate. It also gives you the opportunity to set a specific sport mode using its 14 preset options and track the distance you covered.

The watch allows you to check weather, check time, control music, and ability to read and send messages. It comes with a large display screen size of 1.54-inch which allows you to easily call and message instantly. The good part is that this smartwatch takes just two hours to charge fully, while it takes 7 days to drain when in use, and 20 days when on standby.

The Samsung Galaxy Watch 4

The Galaxy Watch 4 from Samsung happens to be one of the most successful morels made by them. It comes with a blood pressure monitoring sensor which provides its users with clear and exact results. Watch 4 can check your heart rate and has an ECG sensor that can take care of your cardiac health and provide you with accurate results.

It also features the ability to call and send text messages, stream music and videos, check weather, GPS tracking sensor, and fitness tracker. The watch is also compatible with Android version 6 and comes with a RAM storage of about 1.58 GB which allows you to have enough storage.

How to use Blood Pressure measurement features on smartwatches?

Now you know how a smartwatch measures blood pressure, but how do you use the blood pressure measurement features on smartwatches?

Almost all the smartwatches on the market will come with instructions on where and how you need to position the watch on your wrist to get accurate blood pressure measurement data. However, to measure blood pressure accurately, you are required to mount the smartwatch sensor under its body, by ensuring that the sensor is pressed against the skin.

Once it is properly done, the optical heart sensor will emit a green light to penetrate via the skin. When it measures the blood flow rate in your body, then the blood pressure cuff will automatically inflate, deflate, and measure your blood pressure.

What are the advantages of using smartwatches for Blood Pressure measurement?

1.       They are user friendly

2.       Smartwatches keep you alert

3.       They can help you in adjusting your fitness program.

4.       They give you the ability to check your blood pressure at any time, from anywhere.

5.       They provide you with a clear picture of your heart health.

6.       They allow you to monitor your blood pressure from home without consulting a doctor.

7.       Very good for managing high blood pressure and other health related issues.


What are the Disadvantages of using smartwatches for Blood Pressure measurement?

1.       Every brand is different and uses various features.

2.       Smartwatches require frequent software updates.

3.       They are a bit expensive, especially those made by known brands.

4.       Shorter battery life which means you have to be charging frequently

5.       They are sensitive to movement

6.       Smartwatches blood pressure results are not as precise as a sphygmomanometer.


How does smartwatch Blood Pressure measurement affect the user experience?

As you know, a consistent management of blood pressure (BP) happens to be the most effective way to prevent stroke and cardiovascular disease. This is because when you start monitoring and managing your blood pressure yourself, you will minimize the risk of having hypertension.

Blood pressure measurement features on smartwatch has helped users in:

1.       Having early diagnosis

2.       Track treatment

3.       Controlling hypertension

4.       Cutting down on health care costs

5.       Checking when there’s blood pressure differences with the one given by a medical expert.


Smartwatches have certainly changed the way we care about our health and fitness. But how does a smartwatch measure blood pressure? This little device can help you to keep track of your blood pressure in many ways.

The good part is that the blood pressure monitors on smartwatches are frequently more user-friendly than manual devices. Whether these watches help you in losing weight or monitoring your health, they have proven to be very useful.

However, the most important goal is to better understand how stress can affect blood pressure readings, and find ways to gather data for more research to improve blood pressure measurement in the future.

Even though blood pressure measurements on smartwatches can provide you with accurate readings, there’s no findings that have proven this to be true. It is very important you get more accurate, consistent, and reliable results by consulting a medical expert. Another way is to choose a device that’s specifically made for the measurement of blood pressure, instead of purchasing a watch with this feature.