An NHS doctor has revealed the 'number one sleep hack' he swears by when he's working night shifts. Dr Arthur, an NHS Paediatrics trainee, regularly shares educational videos on TikTok as @dr_arthur_. According to the doctor, there's a 'life-changing' hack that could improve your sleep, and it's one he uses to drift off instantly.

Sharing his tip, Dr Arthur captioned his post: "This is how to do 'cognitive shuffling', a sleep technique that will change your life!" In his video, the doctor explained: "This is how I've learnt to get to sleep in a matter of minutes as a doctor that does loads of night shifts and is chronically sleep deprived.

"It's called cognitive shuffling, and essentially, the way it works is it distracts your brain, letting your brain know that it is safe to go to sleep. It is getting it away from that anxious state of fight or flight that makes your thoughts race around your head and keeps you up literally all night worrying about things."

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Dr Arthur continued: "To do cognitive shuffling, all you have to do is think of a completely random word and then visualise the thing that that word represents. From there, think of a second word, a third and a fourth. They're all completely unrelated. The aim here is to give random thoughts to your brain to stop it from being anxious and allow you to get off to sleep.

"An easy way that I find is to try and visualise a word that starts with the letter of the last word. So if we start with elephant that ends in a T, we go to tree that ends in an E. We could do elephant again, but let's try and mix things up. Engine.

"Then from that, so on and so on, and keep going until you go to sleep. It will take you a matter of minutes. And I promise you, it will surprise you just how easy this technique is to do and how well it works."

The video proved popular with social media users, gaining over 10k likes. Someone replied: "I do this though the alphabet and have different themes, animals, anatomy, countries, foods." Another commenter shared: "I spell random words backwards, seems to work for me."

Explaining why cognitive shuffling could improve sleep, Calmsays: "Dr. Luc Beaudoin, a cognitive scientist, while researching how the brain transitions to sleep. His findings revealed that as we're about to doze off, our thoughts naturally become less structured and more random. After he found this out, he came up with this method to help speed up this process by nudging our brains into that disorganised, dreamy state earlier."

Calm adds: "1. Start off by picking a simple word like 'door' or 'lamp.' Next, break it down by focusing on each letter of that word and thinking of other words that start with that letter.

"If you choose the word 'lamp,' you could think of 'lemon,' 'ladder,' 'laptop,' etc. Once you can't think of any other 'l' words, move onto 'a' words, then 'm' words, and then 'p' words. 3. Keep going until the randomness of this mental exercise gradually makes you lose focus."