Early stage of lung adenocarcinoma is often accompanied by fever, cough, hemoptysis, chest pain, shortness of breath, wheezing, and significant body wasting, and cough is the most common symptom in early stage. In the middle stage, it is often accompanied by internal lymph node metastasis, which causes chest pain, dyspnea, dysphagia, hoarseness, pleural effusion, superior vena cava obstruction syndrome, and brachial plexus nerve compression sign. Remote metastases, such as brain metastases, bone metastases, liver metastases, and supraclavicular lymph node metastases, are usually late. Brain metastases are often associated with headache, nausea, vertigo, diplopia, seizures, personality changes, weakness of one side of the limb, and bladder and bowel dysfunction. In the case of liver metastasis, symptoms such as loss of appetite, liver pain, hepatomegaly, jaundice and ascites may occur, while in the case of bone metastasis, symptoms such as bone pain may occur. Lung adenocarcinoma is mainly treated by surgery in the early stage, chemotherapy in the middle stage and radiotherapy in the late stage.