Heartburn is most often caused by gastroesophageal reflux disease (GERD), in which the lower esophageal sphincter weakens or relaxes, allowing acidic stomach contents to flow backwards up into the esophagus. Dietary treatment of heartburn involves avoiding foods that cause the lower esophageal sphincter to weaken or which produce excess acid in the stomach. These foods include chocolate, peppermint and peppermint products, tomatoes and tomato products, citrus fruits and juices, coffee, fried and fatty foods and alcohol.
Other factors that increase the likelihood that stomach contents will back up into the esophagus and cause heartburn are having an over-full stomach, bending forward or lying down soon after meals, and being overweight or pregnant. A hiatal hernia, the result of an outpouching of the upper part of the stomach into the chest cavity, also can produce a "burning sensation," or heartburn.