Cough: It is a common symptom of early lung cancer. Patients suddenly develop unexplained dry cough, choking cough and anti-inflammatory treatment is ineffective, or the existing chronic cough suddenly changes in nature. Chest pain: In more than half of the patients with early stage lung cancer, chest pain can be the first symptom. Blood in sputum: Sudden blood in sputum with irregular intermittent unbearable chest pain with no obvious reason should be alerted to the early symptoms of lung cancer. Fever: Some early symptoms of lung cancer manifest as fever. One of the causes of fever is inflammatory fever caused by obstruction of bronchus by lung cancer mass or compression of the wall by lung cancer mass, and the other is so-called cancer fever, which is cancer fever caused by toxins produced by necrosis of lung cancer tumor and often appears after extensive metastasis at a later stage. In addition to appealing bronchopulmonary cancer symptoms, sometimes, individual patients may also have some extra-pulmonary symptoms or metastatic symptoms due to early metastasis, however, for most of the lung cancer patients, until late stage, the systemic symptoms are not obvious, generally there is no wasting, weakness and other symptoms, and there is no obvious whistling dysfunction. If the disease develops to an advanced stage, there will be pleural compression, producing chest fluid, invasion of the chest wall may lead to rib destruction and semi-severe chest pain; invasion of the recurrent laryngeal nerve may lead to hoarseness, compression of the superior vena cava may lead to facial swelling, thick neck and other superior vena cava compression, and if brain and bone metastases occur, there will be corresponding symptoms. These late symptoms are more easily detected and diagnosed. Therefore, it is important for men and women over 50 years old, especially those with high incidence of lung cancer, to learn some tumor knowledge and grasp some early warning signs of lung cancer and other cancers. If there are warning signs, you should catch some of them and seek medical attention in time to trace them to the end. Most of the lung cancers found out in this way by the warning signs are early stage and have good treatment effect.