Hello dear and welcome to the medhelp forum. This is a dangerous game with possible life threatening consequences. There can be direct trauma to the brain and indirect brain damage due to intentional hypoxia from breath holding etc. Kindly educate your child as an elder and get him from indulging in such mindless and dangerous sport, fad or no fad. Wishing you all the best in your Endeavour.
"Dangers: The “game” has lethal consequences. Brain damage or permanent neurological disabilities due to the lack of oxygen is a possibility and each year is responsible for a large number of juvenile deaths."
--Michele Borba, Ed.D.
So, to answer your question: Yes. Absolutely. It's every bit as dangerous as drugs and alcohol. This quote is about the choking game. Don't kid yourself here either, because what the kids are doing tantamounts to the same thing as the choking game that many kids do. This is because it's another form of deliberately cutting off oxygen to the brain to get that high that kids are looking for. Kids don't often think about the long-term affects of the various ways they intentionally get high these days.
A good question to ask yourself is: Why would you want to risk your life and quality of life in your future just so the popular kids in your school will "accept" you? Anyone who is pressuring you into joining you in any of these activities is not a true friend.
Have you ever heard the saying that "Being honest may not get you a lot of friends, but it'll always get you the right ones"? This will always be true your whole life. Being honest means no white lies, no deceit, not covering up a "friend's" crime, and not looking the other way when you know someone is doing something that can harm themselves or others. You're old enough to think about what this means concerning this activity going on in your school among your friends or peers. Something to consider along with this: Would you rather have your friends mad at you or dead? You do not want to carry a heavy burden of guilt on your conscience for the rest of your life, especially when you are still at such a young age.