A bad stomach can be a result of conditions such as gastroesophageal reflux, chronic gastritis, and gastric ulcers, which often cause symptoms such as reflux, heartburn, nausea, vomiting, loss of appetite, and epigastric discomfort. 1. The most characteristic symptoms of GERD are reflux and heartburn. Refluxed gastric juices can irritate the esophagus causing severe stabbing pain behind the sternum, and can also cause laryngitis, chronic cough, asthma or dental erosion. Prolonged irritation of the esophagus can cause spasm or narrowing of the esophagus, and eventually progressive dysphagia may occur. 2. Chronic gastritis is characterized by epigastric discomfort, nausea, acidity, belching or loss of appetite; in severe cases, it may be accompanied by vomiting of blood or black stools. 3. Gastric ulcers are characterized by dull, distending or burning pain in the upper abdomen. Frequently recurring or periodic attacks, mostly after meals. It may be accompanied by symptoms of indigestion such as anorexia, belching and acid reflux. If any of the above situations occur, please consult a doctor for reasonable and standardized treatment.