A vague pain in the chest may not always be a heart attack. If the pain is caused by heart disease, it usually occurs during exercise, exertion and emotional excitement, and can be relieved after rest or by taking nitroglycerin orally. Besides heart disease, other causes of chest pain include: a. Lung diseases, such as pneumonia, pleurisy, lung tumors, etc. Second, digestive system diseases, such as reflux esophagitis, gastric ulcer, etc. Third, there are also some patients with diseases of the chest wall itself, such as chondromalacia, intercostal neuritis, etc.