The diaphragm is a large muscle at the base of the lungs that contracts every time a person breathes in. As the diaphragm contracts, it becomes flatter. This allows the lungs to expand, causing air to be sucked in. Hiccups are involuntary contractions, or spasms, of the diaphragm. The distinctive hiccup sound is produced by closing of the vocal cords, which occurs almost immediately after the diaphragm starts to contract. Eating behaviors, food choices, air temperature changes and emotional stress are common causes of hiccups after eating. Hiccups that occur only after eating are generally little more than a nuisance. But if hiccups occur at other times as well, see your doctor, as they may indicate the presence of a serious medical condition.
Eating Too Much or Too Quickly
Eating too much at one sitting is a common cause of hiccups. Overeating causes the stomach to expand and become distended. The distended stomach pushes up on the nearby diaphragm, which may trigger contractions of the diaphragm and hiccups. Hiccups are also often caused by eating too quickly. Sometimes this occurs because people who eat rapidly tend to swallow excessive amounts of air, causing the stomach to become distended. People who eat quickly are also more likely to overeat, further increasing the likelihood of a distended stomach and hiccups.
Certain Foods and Beverages
Some foods and beverages can trigger hiccups. Very hot, very cold or spicy foods are particularly likely to cause hiccups. These irritating foods stimulate nerves in the esophagus -- the tube transporting food from the throat to the stomach -- and the stomach itself, leading to reflex spasms of the diaphragm. Liquids that are very hot, very cold or spicy can produce similar effects. Consuming carbonated beverages, such as soft drinks or sparkling water, may also cause hiccups. Air bubbles in these drinks can produce a distended stomach, triggering diaphragm spasms and hiccups. Excessive consumption of alcohol is another cause of hiccups, which may occur because of stomach distention or alcohol's irritant effects.
Sudden Air Temperature Changes
Abrupt changes in air temperature around the time of a meal may also produce hiccups. Sudden air temperature changes can stimulate nerves in the esophagus, as well as in the trachea or bronchi -- the series of tubes bringing air from the throat to the lungs. The stimulation can lead to reflex contractions of the diaphragm. Hiccups may occur when a person goes from warm air to cold air or vice versa. Moving to an air-conditioned restaurant after spending time in the sun, for example, may result in hiccups after eating.
Emotional Stress or Excitement
Hiccups may also be caused by emotional stress or over-excitement. They are particularly likely to occur if these emotions cause the person to swallow air. Emotional stress and excitement at mealtime may, for example, be precipitated by arguments at the dinner table.
Reviewed by: Mary D. Daley, M.D.