Question: what causes the hiccups

Kevin Healy answered on 11 Nov 2014:

Apparently Coughing, eating too fast, intense emotions, fizzy drinks and laughing can all cause hicups. Why we do it is less clear. Hiccups are the involuntary movement of the diaphragm which is the muscle used in breathing. There are two possible reasons for why we hiccup.
The first one is that as babies hicups help us clear air out of our stomachs which a big problem for babies as mums know when trying to “burp” them. We never grow out of this behaviour and so we have to deal with the odd bout of the hiccups as adults.
The other idea is that it is left over from our evolutionary ancestors. When our ancestors first crawled onto the land 350 million years ago and developed lungs, hicups might have helped their weak lungs to breath. A similar type of hicuping can be seen in frogs where they gulp air.
The jury is still out on which one is correct however!