Apple watch users stunned after discovering why device may not work for millions

There's something that might stop millions of people from properly using an Apple watch, and it's angered many.

If you invest the sizeable amount that is required for an Apple Watch, which starts at £399 for the latest Series 9, you'd expect it to work no matter what.

Well, technology isn't all that simple and it turns out that there is one feature on the human body that is the device's kryptonite.

The Apple Watch is still very much in fashion, with many enjoying the convenience that it brings us if our phone is tucked away or in the next room, while several others enjoy the benefits and fitness readings it brings while they exercise.

There's even a version of the watch available for £1,229 that is a collaboration with Hermes, so it's fair to say that the demand for the digital watches are there.

However, a viral video is doing the rounds on X, which shows a man altering his body as he, along with several others, is unable to use the device once it's placed on his wrist for one reason.

If you have a wrist tattoo, you may want to steer clear of buying an Apple Watch. (Jakub Porzycki/NurPhoto via Getty Images)

In the clip, he can be seen undergoing laser tattoo removal, with the caption reading: "Removing tattoo for Apple Watch use".

The man has what looks like a tattoo on his forearm, with the design going across his hands too.

He has drawn a circle on his wrist, presumably where the watch will be, and the machine can be seen breaking down the ink in the area into smaller particles for his immune system to break down, allowing his skin to regain its natural pigment.

Social media users couldn't believe that people with tattoos on their wrists wouldn't be able to use Apple Watches to their full capability, sharing their confusion in the comments.

One said: "That’s actually crazy well that’s good to know before I’ve gotten either."

A second put: "Surprised they haven't fixed this."

Another user shared: "Watch works perfectly but can’t detect pulse properly therefore all workouts are constantly pausing and can’t count calories."

Your best bet is to keep your wrist free of any tattoos if you want an Apple Watch. (Jeremy Moeller/Getty Images)

It turns out that it's all because of the watch's photoplethysmography (PPG) sensors, which use light to detect heart rate and other key information.

Tattoo ink can block light from the sensor, preventing the watch from getting accurate readings.

Apple writes on its website: "Permanent or temporary changes to your skin, such as some tattoos, can also impact heart rate sensor performance.

"The ink, pattern, and saturation of some tattoos can block light from the sensor, making it difficult to get reliable readings."

So if you want to use your Apple Watch to monitor your heart rate, don't get a tattoo on your wrist.

Apple recommends connecting your Apple Watch to a Bluetooth chest strap if you're unable to get accurate heart rate readings from it.