It doesn’t and shouldn’t be life threatening. It’s the feeling of light-headedness that enhances everything else that also surrounds that kink. You’re actually not supposed to choke your windpipe but instead squeeze the sides of the neck to slow down but not stop blood flow. If done right and for short amounts of time it shouldn’t be life threatening at all. Of course with like everything else there’s a lot of people who don’t know/don’t care about the proper way to do it and end up just chocking their windpipe and stopping their breathing, which is extremely dangerous.