Lung cancer does not have any special symptoms in early stage, but only symptoms common to general respiratory diseases, such as cough, sputum and blood, low fever, chest pain and tightness, which can be easily ignored. Specific manifestations of common symptoms of lung cancer in early stage: 1. Cough Lung cancer usually produces irritating cough because it grows on bronchopulmonary tissues, which leads to respiratory tract irritation. 2.Low fever After the tumor blocks the bronchus, there is often an obstructive lobe of lung, the degree of which varies from low fever in mild cases to high fever in severe cases, which may temporarily improve after medication but will recur soon. 3. Chest distension and pain Chest pain in early stage of lung cancer is mild, mainly manifested as boring pain, hidden pain, the location is not certain and the relationship with breathing is also uncertain. If the distending pain continues to occur, it indicates that the cancer may involve the pleura. 4. Sputum blood: When tumor inflammation causes necrosis and capillary breakage, there will be a small amount of bleeding, which is often mixed with sputum and appears intermittently or intermittently. Many patients with lung cancer visit the doctor because of sputum blood. Late stage symptoms of lung cancer: 1. Facial and neck edema There is superior vena cava on the right side of mediastinum, which transmits venous blood from upper limbs and head and neck back to heart. If the tumor invades the right side of the mediastinum and presses the superior vena cava, the jugular vein will initially become angry due to poor return flow, which will eventually lead to facial and neck edema, which needs to be diagnosed and treated in time; 2. 3. Shortness of breath Almost all lung cancer patients with regional spread have varying degrees of shortness of breath. Normal tissue fluid produced by the lungs and heart muscle returns to the lymph nodes in the middle of the chest. If these lymph nodes are blocked by the tumor, this tissue fluid will accumulate in the pericardium to form a pericardial effusion or in the thorax to form a pleural effusion. Both of these conditions can lead to shortness of breath. However, the combination of chronic lung disease of varying degrees in many smoking patients makes the identification of shortness of breath difficult. In addition, the loss of respiratory function due to the growth of tumors in part of the lung tissue can cause respiratory discomfort due to the impairment of the entire respiratory function, which is initially felt only during exercise and eventually even at rest.