【英语时差8,16】打嗝……打嗝……为什么我们会打嗝？（在线收听）

We’ve all experienced them at one time or another, often right after a big meal. A normal bout of hiccups usually lasts only a few minutes and may contain up to seventy individual “hics.” Unlike coughing or sneezing which can help clear your airways, hiccups seem to serve no beneficial function in the human body. What’s the story behind these strange convulsions? Two separate things happen to your body when you hiccup. The muscles in your diaphragm, which normally control your breathing, contract with a sudden jerk. This causes a sharp intake of breath. At the same time, your vocal cords contract to stop this breath, resulting in a loud “hic.” This is all caused by a misfire in the nerves that control your diaphragm. These nerves run from your neck to your chest, and any unusual pressure or irritation along this length can cause a misfire. Hiccups are often triggered by overeating, gulping your food too quickly, or eating something too hot or too cold. Stress can also cause hiccups. There are many folk remedies for hiccups, but none seems to work for everyone. Such remedies include holding your breath, breathing into a paper bag, or drinking a glass of water without breathing. It’s possible that by depriving the diaphragm muscles of oxygen, these remedies force them to resume a more normal breathing pattern. Other remedies include pulling your tongue, sucking a lemon, or having a friend startle you. What these remedies have in common is that they trick your nervous system with a diversion, perhaps shocking the nerves that control the diaphragm into normal behavior. No one knows exactly why these remedies sometimes work. It’s extremely rare, but severe cases of hiccups do occur. If you have persistent hiccups that simply refuse to go away, you should probably consult a physician.