You're eating too fast, you swallow a big gulp of fizzy drink, and suddenly — hic! Your whole body jolts. What on earth is going on? The hiccup might be one of the most pointless-feeling things your body does, but it's not completely random.
Meet your diaphragm
Underneath your lungs lives a large dome-shaped muscle called the diaphragm. Its job is to help you breathe — when it pulls down, air rushes into your lungs. It does this thousands of times a day without you noticing. Normally, it's brilliant at its job.
But sometimes it gets irritated. Eating too quickly, swallowing air, drinking something very cold, or even getting over-excited can cause a sudden spasm — a sharp, involuntary squeeze. That's the hiccup itself: your diaphragm throwing a quick strop.
Why does it make that sound?
When the diaphragm spasms, it sucks air in very suddenly. At the same moment, your vocal cords snap shut to stop all that air rushing straight into your lungs. That closure is what makes the "hic" sound — air hits the closed vocal cords and bounces back noisily.
Think of it like pressing a pump too hard and the nozzle snapping shut. The air has nowhere to go, so it makes a sharp pop. Your throat is the nozzle.
Are hiccups actually useful?
Here's the honest answer: probably not. Most scientists think hiccups are what's called a vestigial reflex — a leftover from our evolutionary past. Some believe it dates back to our ancient fishy ancestors, who used a similar reflex to push water over their gills. We kept the wiring even though we lost the gills.
Today, hiccups serve no obvious purpose. They're just your body's old software running a programme that doesn't really apply any more.
How do you stop them?
Everyone has a method — hold your breath, drink water upside down, get someone to startle you. Do any of them actually work? Sometimes. The goal of all these tricks is the same: to reset the rhythm of your breathing and calm the irritated diaphragm nerve (called the phrenic nerve). There's no guaranteed cure, which is why everyone's nan has a different advice.
The good news? Almost all hiccups stop on their own within a few minutes. Very rarely, hiccups can last hours or even days — in which case a doctor can help. But for the everyday version? Just wait it out.