Symptoms of lung cancer are manifested in cough, blood in sputum, hemoptysis and chest pain. Lung cancer is a malignant tumor originated from bronchial mucosa or glands in the lungs. The cause of lung cancer has not been clearly defined, and it is mostly related to smoking, occupational exposure, air pollution, diet, heredity and other factors. Early stage of lung cancer patients usually have no obvious symptoms, and a small number of patients may have paroxysmal irritating dry cough with no or little sputum. As the disease progresses, some patients may also have symptoms of blood in sputum or hemoptysis, which is more common in central lung cancer. With the development of the disease, when lung cancer invades adjacent organs and tissues, it will also cause pain in the chest, which manifests as irregular hidden pain or dull pain. Since every person is different, the symptoms of lung cancer are also different, and some patients may have symptoms such as dyspnea and fever. If the above symptoms occur, it is necessary to be alert to the possibility of lung cancer, and it is recommended to go to regular hospitals in time for relevant examinations to make a clear diagnosis. In daily life, one should develop good habits and quit smoking and drinking in time.