Pansy I used to do this as a kid, but I would cough and cough till I threw up. I think it started in earnest when I was about 2 and didn't stop till I was 4 maybe 5. I did it to get my own way and boy did it work. My mum now says (with 20-20 hindsight) that she would have ignored me but at the time it really stressed her and dad out.