Heartburn is caused by excessive secretion of gastric acid that stimulates the gastroesophageal mucosa. There are many common diseases, such as gastroesophageal reflux disease (GERD), gastritis, peptic ulcer, peptic tumor and other diseases. 1. Gastroesophageal reflux disease (GERD): improper diet, overeating, anti-reflux dysfunction and other factors may cause abnormal secretion of digestive juices, which may lead to the symptoms of acid reflux heartburn. 2. Gastritis: inflammation of the gastrointestinal tract caused by various reasons can also cause abnormal secretion of digestive juices, leading to heartburn. 3. Peptic ulcer: Commonly, gastric ulcer, duodenal ulcer and other diseases may also lead to heartburn symptoms. 4. Tumors of the digestive tract: for example, esophageal cancer, stomach cancer, etc. can also cause heartburn. Simply based on a symptom can not diagnose the cause of the disease, there may be other factors, you need to go to the hospital in a timely manner to determine the cause of the disease, and follow the doctor’s instructions for treatment.