The difference between too much and too little stomach acid is that too much stomach acid may cause diseases such as peptic ulcer, while too little stomach acid may lead to indigestion, constipation or diarrhea. 1. Excessive stomach acid: i.e. excessive secretion of gastric juice, long-term excessive stomach acid may lead to gastroesophageal reflux disease, peptic ulcer, gastric hemorrhage and other digestive disorders, the common symptoms are heartburn and acid reflux, which can be significantly relieved by eating. 2. Too little stomach acid: that is, insufficient secretion of gastric juice to complete digestion. It may lead to deficiencies of iron, zinc and B vitamins, causing iron deficiency anemia and other manifestations. Long-term low stomach acid may lead to pernicious anemia, chronic gastritis and other diseases. Common symptoms are upper abdominal discomfort, poor appetite (poor appetite) bloating, indigestion, burping, constipation or diarrhea. If there is discomfort from abnormal stomach acid secretion, you should seek medical attention in a timely manner and be treated under the guidance of a medical professional, rather than blindly dealing with it on your own, which may result in adverse consequences.