Scott Crookson, of King's High School, asks :-

Lydia Gallagher, of St Josephs School, Port Chalmers, asked:-

What causes hiccups?

Brian Hyland, a physiologist at the Otago Medical School, responded.

A hiccup is a case of bad timing.

Air and food both go down our throats, but through different tubes. Air in the stomach is not much use and food in the lungs is dangerous. Luckily, the brain systems that organise breathing and swallowing work together to ensure that, mostly, the right stuff goes down the right tube.

When we swallow, the brain automatically turns off breathing (try it -- can you breathe at the same time that you swallow?) and also contracts muscles in our throats to close off the wind-pipe, so food cannot get in. On the other hand, when we breathe, the wind-pipe is left open so air can get to the lungs.

In hiccups, for some reason the windpipe closing mechanism turns on when it shouldn't -- just the beginning of a breath. The effect is the same as if you put the bath-plug back in, when water is still rushing through the plug hole.

Hiccups get triggered by lots of things -- drinking lots, too fast, with big gulps of air, for example. These hiccups can be stopped in lots of ways, ask around to see how many different cures for hiccup you can collect. Unfortunately, some diseases also cause hiccups, sometimes to the extent that drugs have to be given to stop them.