If the patient has prolonged dull pain on the left side of the chest, the following points should be considered: first, the cardiac origin of the disease is considered, such as myocardial ischemia caused by a variety of chronic factors, especially because of coronary heart disease, angina pectoris, or cardiac arrhythmia, chronic heart failure, chronic myocarditis, or the patient due to a variety of reasons for the cardiac valvular disease, will trigger coronary artery ischemia, stenosis, spasm, and when the cardiac muscle cells supply of blood and oxygen is insufficient, the chest will have prolonged dull pain. , when the oxygen supply is insufficient, there will be a long time stuffy pain in the chest. Secondly, if patients have respiratory diseases, such as chronic bronchitis, bronchodilatation, chronic obstructive pulmonary emphysema, pulmonary hypertension, they will also have prolonged tightness and pain on the left side of the chest. Third, for patients with intercostal neuralgia, some patients will also have pain. Fourthly, for patients with cardiac neurosis, they will also have this manifestation when they have vegetative nerve dysfunction.