Hiccups are caused, so ive read, when the diaphragm gets off beat with your breathings and it causes air to build and and when it moved it pushes it out sort of causing a hiccup. Drinking to fast eating to fast and not breathing correctly can cause hiccups. I use to fall asleep in class on my desk and wake up with hiccups because i was compressing my diaphragm
not breathing enough, i think.
thx