Many people want to know what causes heartburn. Heartburn symptoms, such as a burning feeling in the upper abdomen and chest (often accompanied by a pressure sensation), indigestion and chest pain are actually caused by Gastroesophageal Reflux Disease, commonly referred to as GERD. This disease is defined as a condition caused by the reflux (or back up) of stomach contents into the esophagus, causing troublesome symptoms and complications. GERD is often also referred to as acid reflux. In fact, these terms can be used interchangeably. What causes GERD is a malfunction of a muscular structure called the lower esophageal sphincter (LES) located at the end of the swallowing tube (esophagus) at the point where it joins the stomach.
Under normal circumstances, the LES functions as a valve allowing food to pass readily into the stomach while not allowing stomach contents to back up or “reflux” upward into the esophagus. When the function of the LES is compromised, it loses its valve function and stomach contents can move the wrong direction up into the esophagus. The lining of the esophagus is sensitive and not meant to withstand exposure to stomach juices, including acid. It is easily irritated causing many symptoms, the most common of which is heartburn.
The term acid reflux tends to imply that the stomach juice that “refluxes” upward into the esophagus causing symptoms is acid alone. However, the juices that are contained within the stomach include a wide array of chemicals including bile, enzymes and others. While medications can neutralize the acid in the stomach or decrease its production by the stomach, the reflux continues. Although in the majority of situations symptoms are improved, the actual cause of acid reflux is not addressed by the medications. The dysfunctional valve at the end of the esophagus is not changed at all. Therefore, since the valve is not improved these drugs fail in many patients and another approach is needed for relief.
Another common cause of GERD is overeating. Overeating can be a major factor that causes the LES to become damaged. Filling up or stretching of the stomach allows the LES to be exposed to stomach contents including acid, which damages the LES.