Clinically, there are no five physical signals of lung cancer in the early stage. The clinical manifestations of lung cancer are related to the size, type, location and development stage of tumor, etc. Some patients in the early stage have no obvious symptoms, while some patients may have different degrees of cough, hemoptysis, chest tightness and other preliminary manifestations, which can be used as signals suggesting the disease, but they are not limited to five, and usually not specific. It can be used as a preliminary judgment based on the signals suggested below, but when it is not clear, it is recommended to seek medical attention for CT, MRI and other imaging examinations: 1. cough: it is one of the pre-symptoms, mostly manifested as irritating dry cough without obvious sputum, and after the tumor causes bronchial stenosis, it can lead to aggravation of cough with persistent high-pitched metallic sound cough or irritating choking cough; 2. blood in sputum or hemoptysis: it is mostly seen in central lung cancer, lung cancer When the cancer presses into the lung, the performance of blood in sputum may appear. When the surface of the cancer is eroded or when it erodes large blood vessels, patients may also experience hemoptysis; 3. chest tightness and chest pain: some patients have chest tightness as the first symptom, and when the tumor directly invades the chest wall, chest pain may appear, which may be aggravated when breathing or coughing; 4. fever: patients with lung cancer may have fever in the early stage of the disease, and a few of them have persistent fever, mostly due to obstructive pneumonia caused by the tumor, and a few of them may be caused by necrosis of the tumor tissue. It is mostly caused by obstructive pneumonia caused by tumor, and in some cases, it can be caused by necrosis of tumor tissues, and usually antibiotic treatment is not effective; 5. Hoarseness: when lung cancer presses the laryngeal nerve, it can cause vocal cord paralysis and make the patient’s voice hoarse. In addition, patients may also have shortness of breath, wheezing and difficulty in breathing in the pre-lung cancer stage, which need to be carefully distinguished from other diseases of respiratory system. The earlier lung cancer is detected and treated, the better the prognosis. Older smokers or those with lung cancer family messengers should go to hospitals for regular physical examinations to detect any abnormalities at an early stage.