The older we are, the more tips and tricks we've gathered along the way to cure the hiccups. My personal favorites are a spoonful of sugar on the tongue, and drinking a big glass of water while holding one arm up over my head. I like the first because it tastes good, and just about makes my eyes cross with pleasure. The second is a favorite because it's just so silly. Actually, both of these favorites have something in common, and they are at the root of all hiccups cures, as well as being based on sound scientific facts.
Hiccups are caused by a contraction of the nerves leading into one's diaphragm, and are best cured by increasing CO2 levels in the blood, or decreasing the hyperactivity of the nerves making the diagramsa contract. The rapture (and forbidden pleasure) of sugar on the tongue tends to make us hold our breath as we enjoy it. We savor the sugar with breathless delight, CO2 levels increase, and the hiccups disappear. If you think back to all the remedies you've ever been told would cure hiccups, you'll see that all of them involve a voluntary, or involuntary, holding of the breath. At the root of all of them is something that increases CO2 levels, or creates a soothing effect on the central nervous system. Even the old trick of being scared by something causes us to momentarily hold our breath, then continue breathing for a short time afterward with quick, shallow breaths. This, too, increases CO2 in the blood and eases the hiccups. For me, all I need is a family member threatening me with the "scare cure" to chase away the hiccups. I hold my breath, wondering what nefarious plan they have up their sleeve.
In our home, armed with the knowledge of CO2 levels and its effect on hiccups, we tickle each other to end annoying hiccups. I was raised on the old saw that if you tickled someone too long it would give them hiccups, which is probably true. The continual pressure on the diaphragm nerves from laughter, taken to the point of discomfort, will irritate those nerves and cause hiccups. But a light tickling, and the anticipation leading up to them, is also a cure. Laughter increases CO2 levels in the blood. It's not as sweet as sugar, but it is a great way to have fun with family members.
However, this method is not recommended in business situation, especially if your boss is the only one close enough to ask for a quick tickle. In business and social situations, hiccups need to be dealt with swiftly and without drawing attention to oneself. In these cases, it's best to spread the fingers of both hands, place them on the bottom of either side of your rib cage, with the index fingers placed where the bottom ribs begin to turn upward, and your other fingers extending back along the ribs, then press firmly but gently. This is the area where the nerves leading to the diaphragm are located. Firm and consistent pressure on that network of nerves is sure to break their pattern of scrambled firings into your diaphragm.
The fastest, most dignified way to relieve hiccups is by direct calming of the misfiring nerves. The best way is any of the common old wives remedies we've learned along the way. Not only do they all work to some degree by increasing CO2 levels in the blood, they also help to soothe, calm, and bring back memories of family, friends, and the silly things you've done together, the times we've shared together, and the help we've offered and received.