The cough caused by pneumonia itself can cause stomach discomfort and even heartburn and bloating. In addition, patients with pneumonia can have fever, which can cause a systemic reaction that involves the digestive tract and can lead to epigastric discomfort, nausea, and even vomiting. In addition, some pneumonia, such as those caused by viruses and mycoplasma, Legionella, and chlamydia, is a systemic disease that can cause stomach discomfort, as well as affect the liver so that liver function is abnormal, all of which can cause symptoms such as upper abdominal discomfort, nausea, vomiting, and even diarrhea and bloating, which in children and the elderly are mainly digestive symptoms, while actually being infected with pneumonia.