There are many possible factors contributing to indigestion. It may indicate a more serious underlying disorder or can be as simple as irritation caused by a specific food. If you tend to eat large meals or eat too quickly, this can cause indigestion. Foods that are greasy or have a high-fat content can also cause symptoms, as these foods are harder to break down and slow the digestive process. Spicy foods are irritants and can result in a burning sensation in the abdomen. Caffeine, alcohol, and carbonated beverages may also be the culprit, as they can cause an increase in acidity and gaseous build-up. Smoking heavily affects the functionality of the lining of the GI tract, and stress can significantly disturb the neural communication between the brain and the gut. Some medications may also be at the root of your indigestion, including antibiotics, pain relievers, iron supplements, thyroid medications, steroids, and estrogen-containing medications such as oral contraceptives.