Stomach cancer usually does not cause dyspnea. Stomach cancer is a tumor in the patient’s stomach, and the main symptoms are causing stomach discomfort, such as vague pain or distension in the stomach, along with indigestion, nausea, vomiting, acid reflux, belching and other symptoms. There may be choking sensation when eating, mainly in the cardia. There may also be symptoms like pyloric obstruction, and the patient will have vomiting, and the vomit will have persistent food, that is, something that was eaten in the previous days, which will not cause the patient to have respiratory dysfunction. However, if the patient has advanced gastric cancer, the tumor has metastasized to the lung and there are many lesions, it may cause respiratory dysfunction, such as coughing, hemoptysis, or even respiratory distress.