Why do we hiccup?

Biological Insight

A hiccup is, mechanically speaking, a spasm of the diaphragm followed by the sudden closure of the glottis - the flap at the top of your windpipe. This produces the characteristic 'hic' sound and accomplishes absolutely nothing useful for a land-dwelling mammal. The pattern, however, looks suspiciously familiar to biologists who study amphibians. Tadpoles have gills and lungs simultaneously, and they need to breathe through both without getting water in their lungs. Their solution: a motor pattern that closes the glottis immediately after drawing in water. It works beautifully if you're a tadpole. It does nothing if you're a management consultant. The neural pathway for this reflex runs through some of the oldest parts of the brainstem - regions we share with fish and amphibians. When something triggers this ancient circuit (eating too fast, carbonated beverages, stress, or sometimes nothing at all), you begin rhythmically re-enacting a gill-breathing pattern from the Devonian period. The first fish crawled onto land roughly 375 million years ago. Your brainstem has not entirely processed this development. Cures for hiccups - holding your breath, drinking water upside down, being startled - work occasionally and randomly, which is another way of saying they don't work and we don't know what does. The NHS officially recommends 'waiting for them to stop.' This is the same NHS that performs heart transplants. The organizational parallel is almost too obvious: how many of your processes are 370-million-year-old reflexes dressed up as best practices? How many exist because they made sense in a previous environment - one with different pressures, different media, different ways of breathing - and simply never got updated? Most importantly: if someone asked you to justify them, would your best answer also be 'we're waiting for them to stop'?