A valve is at the entrance to the stomach, a ring of muscle called the lower esophageal sphincter (LES). Normally, the lower esophageal sphincter closes as soon as food passes through it. If the lower esophageal sphincter doesn't close or opens too often, acid produced by your stomach can move up into esophagus. This can cause symptoms such as a burning chest discomfort called heartburn. If acid reflux symptoms happen more than twice a week, you may have acid reflux disease, also known as gastroesophageal reflux disease (GERD).
Ayurvedic view of Acid reflux-
From an Ayurvedic view, acid reflux is usually considered an imbalance of the Pitta dosha in the stomach. Pitta dosha represents heat, or the fire element, therefore anything that increases fire element in the body or mind has the potential to cause acid reflux.
