When acidity is not treated properly or at the right time, the excessive acid in the stomach can weaken the defense mechanism of the stomach lining. Ulcers can be formed in the esophagus, stomach and duodenum. GERD is another complication of chronic acidity. Stomach Ulcers are formed when the highly acidic medium of the stomach disturbs its protective mucus lining and exposes the lining tissues to the acid. When the acid is not neutralized by the bicarbonates of the duodenum, ulcers are formed in the duodenal lining also. Gastro-Esophageal Reflux Disease (GERD) also known as acid reflux, is a chronic condition in which the contents of the stomach regurgitate into the esophagus. This happens when the esophageal sphincter fails to block the contents of the stomach from going back to the esophagus. GERD can be caused by various other factors, but can also be one of the complications of poorly treated prolonged gastric acidity. The taste of acid is felt in the mouth along with bad breath. Other symptoms include chest pain, breathing problems, wearing away of the teeth and vomiting.