Body & HealthHow it works
How a hiccup happens and where the 'hic' comes from.
A hiccup is a reflex: the diaphragm contracts suddenly, you inhale sharply, and about 35 milliseconds later the glottis snaps shut. The airflow hits it, producing the sound. The reflex arc runs through the phrenic and vagus nerves and the brainstem. Even foetuses hiccup, probably as training for the breathing muscles.
Useful: Most home remedies work, if at all, through the nervous system, for instance by stimulating the vagus nerve.
Source: en.wikipedia.org