Heartburn, also known as pyrosis, cardialgia or acid indigestion, is a burning sensation in the central chest or upper central abdomen. Heartburn is usually due to regurgitation of gastric acid (gastric reflux) into the esophagus. It is the major symptom of gastroesophageal reflux disease (GERD).

Other common descriptors for heartburn (besides burning) are belching, nausea, squeezing, stabbing, or a sensation of pressure on the chest. The pain often rises in the chest (directly behind the breastbone) and may radiate to the neck, throat, or angle of the arm. Because the chest houses other important organs besides the esophagus (including the heart and lungs), not all symptoms related to heartburn are esophageal in nature.

The cause will vary depending on one's family and medical history, genetics, if a person is pregnant or lactating, and age. As a result, the diagnosis will vary depending on the suspected organ and the inciting disease process. Work-up will vary depending on the clinical suspicion of the provider seeing the patient, but generally includes endoscopy and a trial of antacids to assess for relief.

Treatment for heartburn may include medications and dietary changes. Medication include antacids. Dietary changes may require avoiding foods that are high in fats, spicy, high in artificial flavors, heavily reducing NSAID use, heavy alcohol consumption, and decreasing peppermint consumption. Lifestyle changes may help such as reducing weight.