Acid flux, also known as acid reflux, is a condition in which acid from the stomach moves into the esophagus, explains WebMD. This often causes a burning sensation in the chest, which is sometimes known as heartburn.
According to WebMD, people who experience acid reflux symptoms more than two times a week have acid reflux disease, which is also called gastroesophageal reflux disease (GERD). The symptoms of acid reflux can be treated with antacids, which neutralize the acid in the stomach. Physicians can also prescribe proton pump inhibitors or H2 blockers, both of which reduce the amount of acid the stomach produces.