For every hiccup, there are five cures. Standing on your head, drinking a glass of water upside-down, a digital rectal massage, even Plato wrote of holding your breath. Perhaps the best cure will be found once hiccups are understood. But that’s difficult as there are currently only two hypotheses on their origin.
Our ancestors gulped for air, and we can’t stop!
First, quite entertainingly, is the theory that hiccups are an evolutionary remnant. It’s called the “phylogenetic hypothesis“. When our ancient ancestors first crawled onto land, they gulped air and water across their gills (tadpoles do this because their lungs are not yet fully formed). The hypothesis claims this reflex has remained a part of us ever since!
Infants spend about 2.5% of their time hiccuping.
Infants hiccup often. This could be evidence for the phylogenetic hypothesis (as their lungs have not formed, in the same way as our ancestors), but it has led to another hypothesis. Infant mammals drink milk, and by hiccuping they release air in their stomach to make room for more milk. The fact that only milk-drinking mammals seem to hiccup would support this idea.
Whatever the case may be, hiccups are here to stay.