Is it possible....?!
Question: To kill yourself by holding your breath?
Answers: To kill yourself by holding your breath?
No...eventually you will pass out and your body will start breathing again on it's own.
Reflexes will make you open your mouth but technically yes, if you can find a forceful enough way to block off your airways. Clamp your nose and tape your mouth or something.
Because your body operates with the co-ordination of involuntary muscle [behavior/response] & voluntary you can not simply stop breathing & die by holding your breath...Lucky you huh~ Take care! And breathe~