Acid Reflux or Heartburn is a painful or burning sensation in the esophagus, just below the breastbone caused by regurgitation of gastric acid.
The sensation of heartburn is caused by exposure of the lower esophagus to the acidic contents of the stomach. This is also known as acid reflux.
Normally, the lower esophageal sphincter (LES) separating the stomach from the esophagus is supposed to contract to prevent acid entering the esophagus. If the sphincter relaxes for any reason (as normally occurs during swallowing), stomach contents, mixed with gastric acid, can return into the esophagus. This return is also known as reflux, and may progress to gastroesophageal reflux disease (GERD) if it occurs frequently. Peristalsis, the rhythmic wave of muscular contraction in the esophagus, normally moves food down and past the LES and is responsible for ultimately clearing refluxed stomach contents. In addition, gastric acid can be neutralized by buffers present in saliva.
Gastroesophageal Reflux Disease
Gastroesophageal Reflux Disease (GERD; or GORD when spelling oesophageal, the Barrett's esophagus,BE, form) is defined as chronic symptoms or mucosal damage produced by the abnormal reflux of gastric contents into the esophagus.
GERD is commonly due to transient or permanent changes in the barrier between the esophagus and the stomach. This can be due to incompetence of the lower esophageal sphincter (LES), transient LES relaxation, or association with a hiatal hernia.