Apple Watch users shocked to discover new app 'knows they're sick' days before feeling any symptoms

People are flooding to social media over an 'awesome' Apple Watch feature which detects when you're sick 'in advance'.

Imagine being able to predict when you were about to get sick, so you could dose up on vitamins and fight off a cold before it even had the chance to fully get going?

Well, apparently an app available on Apple Watch has been alerting users as to when they may be coming down with something.

A Reddit user named u/dalethomas81 took to the thread r/AppleWatch to reveal their 'Vitals app knew [they] were sick three days before [they] did'.

They explained: "Woke up today feeling off. Now as the evening is setting in, I am feeling that old familiar feeling in my head. I’m sick."

And they have the screenshot to prove it, a picture of their Vitals page showing 'three outliers' - results within the person's health data which are abnormal or outside the realms of normal compared to other days.

And it's not taken long for others to weigh in, many with their own experiences of the app.

A Reddit user said: "I started using Vitals when it first came out on the beta and since then I’ve gotten sick about twice. Both times it knew a couple days in advance and I hadn’t felt anything wrong. Kinda insane how useful this feature can be."

"Mine too, I’m still sick but watch noticed before I did," another added.

A third questioned: "Is it a high wrist temperature that tips you off?"

The original poster responded: "Yes. It’s kind of hard to see but in the bottom of the screenshot it shows the temperature as being the culprit."

A fourth questioned: "This is awesome, but what are the best actions you can take with this info to help limit the sickness?"

And the OP resolved: "Along with what others are saying, you can also limit other people’s exposure. I have a wife and 3 kids and it would be helpful to keep my distance."

If you're a lucky Apple Watch wearer and want to have a go at looking deeper into the feature, Apple's website explains: "You can also tap Overnight Vitals, then tap More Info to learn about what results you may see, what it means when your overnight vitals are outside of your typical range and the lifestyle factors that may affect your results."

However, it also notes 'Vitals app measurements are not intended for medical use' and advises to 'consult your healthcare provider prior to making any decisions related to your health'.