Trapped air isn't it Nat? That's why you make people jump or focus on a silly task cause it means they either let the air out or get their breathing back to normal.
At least that's what I think it is but no doubt some well informed person will come with the correct scientific answer!
you know what,i had them the other week when i was out my friend said she will get me a cup of water and give it to me,she held the cup and i drank it all well the bloody things went.you get them as well if you eat too quickly too
Isn't it to do with inhaling to deep and too suddenly which then causes your diaphragm to go into spasms? I thought that was it, but then I know that so many things can cause hiccups (e.g. eating too fast, fizzy drinks, over-excitement, cold showers). I'm not sure if all of these would cause you to inhale too deep and too suddenly. Hmm....
What I mean is, I definitely know that the actual hiccup is your diaphragm muscles going into spasm. What actually causes the hiccup to start could be anything! I only ever get them when very, very drunk. :o}
Basically no-one knows what hiccups are for, as they serve no useful purpose as far as scientists can tell. They're spasms of the diaphragm, and can be caused by loads of things, notably eating to fast.
Not sure what causes hiccups, but you can get rid of them by holding your fingers in your ears, and getting someone else to hold a glass of water for you to drink. You'll need to gulp the water down quite quickly though.