Your diaphragm is a muscle that helps with inhaling and exhaling. Hiccups happen when your diaphragm suddenly contracts, followed by the shutting of your vocal cords. Air gets trapped in your throat and you hiccup. No one fully understands what causes hiccups, although some triggers have been identified. For short-term hiccups, time usually causes hiccups to stop on their own. A number of home remedies that increase the amount of carbon dioxide in your blood are considered reliable, too. For example, some people hold their breath for 10 seconds; some breathe into a paper bag for a little while; some eat a teaspoon of sugar; some drink a cold glass of water quickly; and some like to get scared since the fright-induced gasp forces them to take in a lot of air at once.
For hiccups that last longer than 48 hours, intervention is often necessary. First, the doctor has to figure out what's causing the hiccups. If you're ill, getting rid of the sickness might also get rid of the hiccups. Otherwise, some drugs are used to treat chronic hiccups, including an antipsychotic called chlorpromazine, an anti-nausea medication called metoclopramide and a muscle relaxer called baclofen.
In some extreme cases, surgical procedures can become necessary. If your hiccups are caused by a distended stomach, doctors can insert a thin tube down your nose into your stomach, called a nasogastric tube, which may get rid of hiccups. Another option is to inject an anesthetic into your body to block your phrenic nerve, which is related to hiccups. Plus, there's a procedure called vagus nerve stimulation; in this operation, a device is implanted in your chest that electrically stimulates your vagus nerve to stop hiccups.