Huawei Watch D2 tested: This smartwatch keeps an eye on your blood pressure

The Huawei Watch D2 can perform 24-hour blood pressure measurements - comfortably and quietly on the wrist. It has an air cushion in the wristband. This inflates and accumulates the blood, which is necessary for measuring blood pressure. This is one of the reasons why the D2 has been approved as a medical product. It also offers other fitness and health functions and acts as an extension of the smartphone - as befits a smartwatch.

No authorisation in Switzerland: The Watch D2 is considered a medical device for which the corresponding certifications must be available. Huawei has applied for and received this in the EU. The manufacturer has not done this for Switzerland, which is why the watch cannot be sold there.

The most comfortable blood pressure monitor

I'm one of the majority of people who don't check their own blood pressure. A measurement at the doctor's or, as this year, during my hospitalisation are the exception. According to estimates by the German Hypertension League (DHL), around a third of the population is affected by high blood pressure. Among the under-50s, to which I belong, the figure is 22 per cent - not including undiagnosed cases. The DHL assumes that the number of unrecognised cases across all age groups is around 20 per cent.

The blood pressure monitors available for home use are sometimes significantly cheaper than the Huawei Watch D2, but they don't appeal to me at all. Their aura says: hospital or retirement home. I'd rather take the opportunity to try out this special smartwatch.

For a useful measurement, the Huawei Watch D2 must fit well. However, I cannot adjust the size via the clasp, as it is a closed bracelet. I have to loosen one of the elements that secure the air cushion in three of the holes in the strap. Now I can move the clasp in these holes. Once I have found the right size, the watch sits comfortably on my wrist.

To measure my blood pressure, I sit down on a chair and sit still for about five minutes. Ideally, you should take the measurement in the morning or evening, when your blood pressure has not yet risen or returned to normal. It is important not to cross your legs and not to sink too much into the chair. However, leaning slightly is fine.

For the measurement, the air cushion must be at heart level. It has the same function as the cuffs of conventional measuring devices that are attached to the upper arm. It ensures that the blood is dammed up so that the blood pressure can be measured. The reading is given in "mmHg" or, written in full, millimetres of mercury.

So I lift my arm with the Watch D2 and can rest it on my shoulder or support my elbow with my other hand. If the position is not correct, the Watch D2 cancels the measurement. If everything is correct, the measurement takes less than a minute.

I start the measurement and feel how the air cushion inflates and firmly surrounds my wrist. Once the process is complete, the firm grip is released and the Watch D2 vibrates. This is necessary because I can't look at the display during the measurement. For the moment, I am in the best of health. Throughout the entire test, my values remained below the recommended average of 135/85 - and with a few exceptions, even below the value of 130/80, which is considered optimal.

Huawei states that the Watch D2 has a deviation of +/- 3 mmHg. A deviation of +/- 10 mmHg is permitted for approval as a medical device. I can't write the scientific study on this, but initial experiences sound promising. At an appointment organised by Huawei, paramedics measured the blood pressure of those present. Firstly in the traditional way with a stethoscope and finger on the wrist. Then with the Watch D2 and a measuring device for home use. The smartwatch was always closer to the manually measured value, which is considered to be very reliable.

My quietest 24-hour blood pressure measurement

I haven't taken a blood pressure measurement for 24 hours for a few years now. The device I wore was uncomfortable and very noisy, especially at night. Instead, the Watch D2 sits almost unnoticed on my wrist and, according to Huawei, is 61 per cent quieter than other 24-hour monitors. I don't hear its pump at all during the day and at night it is so quiet that it doesn't bother me.

In the settings, I can choose between automatic and manual measurement - at least during the day. If I opt for manual, the smartwatch waits with the measurements throughout the day until I have positioned myself and given my OK.

With the automatic option, the Watch D2 starts a measurement at predefined intervals. If I don't assume the correct position quickly enough - smartwatch at heart level - it cancels the measurement. But don't worry, 20 measurements during the day and 7 measurements at night are sufficient for a medically analysable 24-hour protocol. The watch always measures automatically at night, and I can set the times for this.

Another advantage of the smartwatch and the Huawei Health app comes into play when analysing the data. I first have to hand in the conventional measuring device to receive the analysis. With the Watch D2, I can see the measured values directly. However, the final evaluation is still the responsibility of your doctor. The export function for the measurement results is helpful here. I can send them as a PDF or print them out.

Activities for blood pressure: the Watch D2 as a sports watch

My blood pressure readings are very good. Nevertheless, I'm looking at what the Watch D2 can do as a sports watch. After all, exercise, along with a healthy diet, is considered a remedy for high blood pressure. If this is present, the smartwatch from Huawei can not only measure it, but also help to combat it.

With its sensors - Huawei summarises them as the TruSense system - the watch monitors other health data such as pulse, oxygen saturation, stress and sleep. It also registers movement and tracks sporting activities. Instructions for exercises and more detailed analyses are also available in the Huawei Health app.

Running courses, for example, are pre-installed on the Watch D2, as are warm-up and stretching exercises for before and after running, cycling or jumping rope. Other guided workouts are sometimes linked to a paid plan - €7.99/month or €59.99/year - of "Huawei Health+". When you buy the Watch D2, you get three free months to try it out.

Compared to its predecessor, the display of the Watch D2 has become larger and measures 1.82 inches diagonally. The case is still slightly smaller. The watch also sits comfortably on the wrist during sport, although I have to try it out a little before I can decide on one of two size settings. The display is bright and shines in vibrant colours. Together with the large display, this ensures that I can quickly recognise the current data when I'm out jogging, for example.

Immediately after running, the Watch D2 suggests stretching exercises. However, these are too subtle for my body. I prefer to stick to my own selection. When I'm out and about, the intermittent announcements are too loud for me, but they can be turned down or switched off completely in the settings. I also have to activate the automatic pause in the settings before my second run so that red traffic lights don't mess up my pace.

The integrated GPS of the Watch D2 takes about a minute to establish a satellite connection - a good time for the suggested warm-up exercises. The smartwatch records my running route through the city very accurately.

In total, I could record over 80 different sports with the Huawei Watch D2. The number is partly driven up by the distinction between indoor and outdoor - for example when cycling. But what strikes me above all: Swimming is missing! The Watch D2 is not suitable for swimming pools. However, briefly rinsing off sweat under the tap after sport hasn't done me any harm so far.

Long battery life for a smartwatch

In my case, the Huawei Watch D2 used about 14 to 16 per cent of its battery per day. This results in a total runtime of just over six days. Of course, this depends on the respective usage. For example, I activated all available sensors. The GPS probably has the biggest impact on battery life. I only activated location tracking when running and was only out and about for around 30 minutes at a time. Longer use should have a greater impact on battery life.

I hate smartwatches that I have to charge every day. So the Watch D2 is very convenient for me. It's usually enough to connect it to the wireless charger supplied once or twice a week for an hour. This adheres magnetically to the back of the watch. However, the closed standard wristband does not allow the watch to be laid flat.

Expandable smartwatch

The Huawei Watch D2 doesn't just keep an eye on my health and fitness. It's also an extension of my smartphone. At the very least, I can choose which notifications from my mobile should be displayed on the watch

I can also make calls via the Watch D2 and the Bluetooth connection to my smartphone. The watch's loudspeaker is loud and clear. Its microphones pick me up clearly when I hold it in front of my face. I also don't have to speak directly into the watch. Nevertheless, I would only use the function when I'm alone, as people nearby can hear everything.

With the Watch D2 I can control the music playback on my smartphone. Or play music directly from the watch. It plays songs in MP3, AAC, WAV, FLAC and OPUS formats.

Most of the pre-installed apps fit in with the Watch D2's focus on health and fitness. A small selection of 13 apps are available for installation in Huawei's "AppGallery" app store. Among other things, they offer control over the smartphone camera from the wrist or bring Google Maps and calendar to the smartwatch. One particularly negative aspect I notice is that the Huawei Wallet, and therefore the payment function on wearables, is not available in Europe.

Only a small selection of bracelets

The straps of the Watch D2 are theoretically interchangeable. The release mechanism is easy to operate without tools. However, the selection of straps with air cushions is still very limited. To be precise, Huawei is only planning to launch a second model in the near future.