What is a hiccup?

Medically know as synchronous diaphragmatic flutter, hiccups can give you a fright!


Asked by: Dian Milstead, Glasgow

A hiccup comes from an involuntary contraction of the diaphragm, producing a sudden intake of air.

The glottis (the vocal apparatus of the larynx) slams shut at the same time, so that the column of air strikes the closed glottis to produce the characteristic, onomatopoeic noise.

Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.