In the late stage of lung cancer, if the primary lesion is small and does not invade and compress the surrounding blood vessels and nerves, there may be no obvious clinical symptoms, while distant metastasis, such as bone metastasis, brain metastasis, etc., may occur at this time, and there may be no symptoms if the metastatic foci are located in non-important parts. Some patients with advanced lung cancer often do not have clinical symptoms, which is because the tumor foci are small and do not invade and compress the surrounding important tissues, and the patients will not have the clinical manifestations of cough, chest tightness, dyspnea and hemoptysis. If the tumor cells are not located close to the pleura, the patient will also not show symptoms of chest pain. When advanced metastatic lesions are small or located in non-vital areas, there may not be corresponding symptoms, such as smaller brain metastases may not have headache, dizziness and other symptoms. Therefore, early detection of cancer is very important, and it is recommended to have regular medical checkups for early detection, early diagnosis and early treatment.