Chest pain for two or three years is not necessarily lung cancer, but it cannot be completely excluded. Chest pain can be caused by lung cancer, coronary heart disease and intercostal neuralgia. 1. Lung cancer: Early stage of lung cancer may have no symptoms or occasional chest pain, with the prolongation of time, chest pain will be obvious or frequent, typically accompanied by coughing, coughing up sputum, especially sputum with blood, low fever, dyspnea and systemic metastatic symptoms. Lung cancer cannot be discharged immediately by the duration of chest pain, and the diagnosis depends on imaging examination, bronchoscopy or thoracoscopic biopsy. 2. Coronary heart disease: it is a common cause of chest pain. Usually, stable angina has a clear trigger, relieved after resting, and the flaky pain in the precordial area can radiate to the fingers, behind the ear, etc. It can gradually develop into unstable angina. It can gradually develop into unstable angina or myocardial infarction. 3. Intercostal neuralgia: related to viral infection, trauma, spinal lesions, etc., exertion, cold can be heavier, slightly relieved after rest, without timely treatment can recur, prolonged chest pain discomfort. Chest pain for two or three years, there may be other diseases, such as blood system diseases, it is recommended to consult a doctor in a timely manner, improve the relevant examination, identify the causes, under the guidance of the doctor’s scientific treatment.