When you hiccup, the diaphragm undergoes a series of spasms, but you can fool your body into stopping that reaction by putting a teaspoon of sugar underneath your tongue. The sweet sensation is strong enough to stimulate the vagus nerve. That’s the longest cranial nerve in your body, starting at your brain stem and extending as far down as your diaphragm to control the stomach. “Keep the sugar under your tongue until you stop hiccupping, and then swallow to fill the back of your throat with even more sensation .