Symptoms due to primary foci of lung cancer: 1. cough, mostly irritating cough 2.Blood in sputum, mostly blood sputum. 3. Chest pain, generally light and vaguely localized. When the cancer tumor invades the pleura and chest wall, the pain increases, and the localization is clearer and more constant than before. 4.Shortness of breath, which can be caused by pneumonia, pulmonary atelectasis, malignant pleural effusion and diffuse alveolar lesion due to cancer tumor obstruction. 5.Fever, caused by obstructive pneumonia or cancerous toxin. 6.Patients with advanced stage may have more obvious cachexia. Symptoms caused by cancer tumor invasion and metastasis: 1.Superior vena cava obstruction syndrome: right upper mediastinal lymph node metastasis compression or right upper lung cancer tumor directly invades the superior vena cava, resulting in superior vena cava reflux obstruction, causing head and neck swelling. 2.Hornor’s syndrome: sympathetic nerve involvement in the paravertebral sulcus from the seventh cervical vertebra to the first thoracic vertebra, causing ipsilateral pupil narrowing, upper eyelid ptosis, eye entropion and reduced sweating. 3.Pancoast’s syndrome: a symptom group specific to carcinoma of the superior pulmonary sulcus (apical lung), with pain in the ipsilateral shoulder, arm, and upper chest wall, as well as ipsilateral Horner’s syndrome. 4. Hoarseness: caused by the involvement of the laryngeal recurrent nerve. 5.Other: When lung cancer metastasizes to brain, bone, liver and other organs, corresponding symptoms may appear. Concomitant symptoms: Lung cancer may produce abnormal bioactive substances and cause systemic clinical manifestations. 1. Hypertrophic osteoarthropathy, pain in large joints of long bones, pestle-like fingers (toes). 2.Carcinoid syndrome: manifested as abdominal pain, diarrhea, facial flushing, bronchial asthma. 3.Gynecomastia, unilateral or bilateral. 4, other: a few may have hypercalcemia, dermatomyositis, Cushing’s syndrome, etc.