TikTok knockout challenge: What is the trending online game one doctor called 'deadly'?

TikTok is full of trends and challenges, with users sharing them globally and encouraging each other to give them a try. Some are perfectly harmless, such as the Madonna squat challenge, some are more problematic, such as the Taylor Swift cat trend, but some could be fatal - and there are sadly numerous examples of the latter.

Two teenagers called Brooke Ryan and Esra Haynes died after participating in the chroming challenge.  Leon Brown lost his life last year after attempting the blackout challenge. Jacob Stevens died after trying the Benadryl challenge and Christy Sibali Dominique Gloire Gassaille died after taking part in the scarf challenge. And it was thought Archie Battersbee had also taken part in the blackout challenge, before a coroner ruled this out.

Now, health experts have warned people not to get involved with another trending “game” which could prove “deadly” - the knockout challenge. But, just what exactly is it and what have the experts said about it? Here’s what you need to know.

Warning: Please do not take part in the challenge described in this article as it could cause serious harm and may even be fatal.

What is the TikTok knockout challenge?

The knockout challenge has been given its name because participants are meant to be knocked out - but only for a brief time. This isn’t about anybody getting punched though, the intention is for the person doing the challenge to pass out.

It takes two people to complete the challenge and involves one person pressing on the other person's chest until they faint and fall over due to lack of oxygen. This person is only supposed to remain passed out briefly and then they are meant to be revived by others.

It has existed for more than a decade under different names, including being called the choking game and the pass-out challenge. The supposed game first appeared on TikTok under the name “knockout challenge” in 2020 and has since started trending again.

What have experts said about the knockout challenge?

Two doctors who spoke to NationalWorld warned people against taking part in this challenge, and said the consequences of doing so could be extremely severe or even fatal.

Dr Hana Patel, NHS GP and a GP expert witness, called the online game “deadly”. She said that if people restrict their breath until they fall unconscious this can cause low levels of oxygen in the brain - and that can lead to seizures, serious injury or death.

She added: “It’s mimicking suffocation. Participants are stopping the chest muscle from moving, which stops the chest from working and you can't get oxygen to the brain. The brain is then starved of oxygen and the person loses consciousness.

“Any activity that deprives the brain of oxygen has the potential to cause moderate to severe brain cell death leading to permanent loss of neurological function ranging from difficulty in concentration or loss of short-term memory capacity through severe, lifelong mental disability to death.”

She also urged people who may be concerned that their friend, relative or loved one is participating in the challenge to get help or advice from their doctor.

Dr Ross Perry called the trend “one of the worst TikTok trends to be doing the rounds by far”.

 He added: “It is so dangerous and should in no way be attempted by anyone. The consequences of this going wrong are devastating. In most cases of attempting this the person faints and, as this is meant to be short lived, it means the person can be easily woken up. However, due to the lack of oxygen being unable to reach the brain during this time, it can result in brain damage and even death. 

“Ultimately,  If you have low oxygen to the brain for over three minutes you can get brain damage and if you have low oxygen to the brain for over five minutes it can result in death. Milder symptoms of attempting this include headaches, bloodshot eyes, nausea and disorientation.”

What has TikTok said about the knockout challenge?

TikTok has not commented specifically on the knockout challenge, but they have issued general guidance regarding following trends on their website, as part of their community guidelines.

The message reads: “Some online challenges can be dangerous, disturbing, or even fabricated. Learn how to recognize harmful challenges so you can protect your health and well-being”. People are also advised to think about whether or not the people in the videos have special skills, if something could have gone wrong, and if they are confident that they will be safe if they do it themselves. Another message from TikTok reads “if a challenge is risky or harmful, or you are not sure if it is, don’t do it.” 

At the time of writing, however, on Thursday 31 August, NationalWorld found a number of videos showing people taking part in the challenge still appear on the site when “knockout challenge” is searched for.