There are various symptoms of lung cancer, but none of them is unique to lung cancer patients. Most patients are already in advanced stage when they are found, and the presence of the following symptoms and signs should draw attention. 1.Symptoms related to lung: chronic cough, coughing sputum, blood in sputum, chest tightness, chest pain, shortness of breath. 2. Systemic symptoms: unexplained fever, weight loss. 3.Related symptoms caused by tumor spreading in the thoracic cavity: hoarseness (suggesting laryngeal recurrent nerve involvement), head, face and upper body bruising and edema (suggesting superior vena cava involvement), dysphagia (esophageal involvement), droopy eyelids and sunken eyes (Horner syndrome), shoulder pain and restricted movement (brachial plexus nerve involvement). 4. Signs and symptoms caused by extra-pulmonary metastasis: ① enlarged supraclavicular lymph nodes, ② metastasis to pleura causing chest pain and pleural effusion, ③ metastasis to bone causing bone pain and elevated blood calcium, ④ metastasis to head causing headache, nausea and vomiting. (6) Metastasis to the pericardium may cause pleural effusion, (7) Metastasis to the liver may cause pain in the liver area and increase in transaminases, etc.