Welcome to brain Stuff from How Stuff Works pay brain Stuff. I'm Lauren Vogelbaum, and today's question is how do we get hiccups? Science isn't sure, actually, but it's not that medical science has been ignoring hiccups. When these spasms are frequent or persistent in adults, they can indicate over a hundred different diseases and disorders, from multiple sclerosis to cancer to appendicitis, and hiccups themselves can get serious and what's
called intractable cases. Hiccups don't stop for more than a month and can go on for years without relief, leading to complications like irregular heartbeat, weight loss, insomnia, and emotional distress. Understandably, but okay, science isn't totally ignorant here. We know the basics. Hiccups are reflexive spasms of the diaphragm and glottis and more on both of those in a second caused by
irritation to any of several nerves throughout your body. During normal non hiccuppy breathing, you move air into and out of your lungs, partially thanks to contractions of your diaphragm. It contracts pulling downward as you inhale, giving your lungs room to expand, then releases, relaxing upward and letting your lungs contract as you exhale, and all that air moves through your throat and importantly through your glottis, which is
the opening between your vocal cords. But during a hiccup, at least half of your diaphragm, for some reason, contracts sharply about eighty percent of the time. It's just the left half. Go figure that contraction starts pulling in a deep breath, but that breath gets cut short by the glottis snapping shut about three hundreds of a second later.
The hick sound comes from that sudden closure. In most cases, hiccups are caused by irritation of the frenic nerves, which control the motion of the diaphragm and send your brain sensory information about what's going on in various parts of your neck and body. That irritation is usually from your stomach distending when you accidentally swallow air, or when you eat or drink too much too fast, especially carbonated beverages
like soda or beer. In rarer cases, lots of other irritations can be at fault more serious than having over drank soda or beer, such as infections of or trauma to anything that the fhrenic nerves touch, like a tumor pressing against them in your neck, or pericarditis, which is
the swelling of the membrane around your heart. Irritations of the vagus nerve can also be hiccup culprits, possibly due to its connection to the larynx, along with everything from your small intestine to the inside of your ear, and lots of stuff in between. If you're looking to get rid of hiccups, some of the most common home remedies really are worthwhile. They work by either overloading the frenic or vagus nerves or by interrupting your involuntary breathing cycle.
For nerve overload, try biting into a lemon, placing a spoonful of sugar on the back of your tongue, pulling on your tongue, or having a friend tickle or scare you on the respiratory and try holding your breath, gulping down a glass of water, or breathing into a paper bag. And if nothing works, hiccups generally go away on their own. If they do stick around, for more than forty eight hours see a doctor just in case. The purpose behind
this reflex is still a mystery. Some researchers say that they could be vestigial spasms related to how our amphibian ancestors controlled their gills. Others postulate that they help with breastfeeding. Hiccups can release small amounts of air from the stomach into the esophagus, where it can be exhaled, so hiccups might serve to get air out of baby stomachs, making more space for milk. Today's episode was written by me
and produced by Tyler Clay. To find brain stuff gear, check out our online shop at t public dot com slash brain stuff, and of course, for more on this and lots of other topics about our weird bodies, visit our home planet, how stuff works dot com