Swelling in the diaphragm area is usually caused by spasm of the diaphragm due to various reasons, which is commonly seen in mediastinal diseases, diseases around the diaphragm and other diseases or factors. 1. Mediastinal diseases: the phrenic nerve from the neck to the diaphragm needs to pass through the mediastinum, and mediastinal diseases such as mediastinal tumor, thoracic aortic aneurysm, esophageal cancer, esophagitis and other diseases can stimulate the phrenic nerve to cause diaphragm spasms and diaphragm distension. 2. Diseases around the diaphragm (1) Thoracic diseases: lung infection, pleurisy, pericarditis, myocardial infarction and other diseases produce inflammatory factors that can directly stimulate the phrenic nerve causing diaphragmatic spasm and distension. (2) Abdominal diseases: esophageal hiatal hernia, gastritis, gastric cancer, pancreatitis, subphrenic abscess and other diseases pull and stimulate the phrenic nerve causing diaphragmatic distension. 3. Other diseases or factors: such as epigastric trauma, drugs, autonomic dysfunction and other conditions can also cause diaphragmatic spasm and diaphragmatic distension. It is recommended to go to the hospital for further diagnosis and treatment for swelling of the diaphragm.