Acid reflux is a common sign of the stomach ulcer in which a patient suffers a burning pain in the lower chest area. As the stomach walls are damaged, the stomach acids tend to flow back up into the esophagus or the food pipe. The regurgitation of the stomach acid in the food pipe causes the burning pain and sensation in the chest area. The taste of the acid is often felt in the throat, which might lead to bad breath. However, acid reflux that happens more than twice a week is a symptom of another disease known as gastroesophageal reflux disease (GERD).