Symptoms of mid-stage lung cancer include cough, blood in sputum, chest pain, fever and shortness of breath. As the degree of disease is different, there is some variability in symptoms. Lung cancer is a kind of malignant tumor, the cause of which is not yet clear, but it is considered to be related to long-term smoking, exposure to ionizing radiation, genetic factors and so on. When patients are in the middle stage of lung cancer, common symptoms include cough, blood in sputum, chest pain, fever, shortness of breath, hemoptysis, etc. Some patients may even suffer from dyspnea and hoarseness. When the tumor invades the mediastinum or compresses the superior vena cava leading to obstruction of superior vena cava reflux, it may manifest as edema of upper limbs and face and varicose veins of chest wall, and some patients with serious condition may have headache, drowsiness, blurred vision and other symptoms. Even if they are in the middle stage of lung cancer, the severity of symptoms varies due to the different invasion scope of cancer cells and physical condition. For patients with middle stage lung cancer, they should actively cooperate with doctors to take treatment measures to control the progress of the disease and improve the 5-year survival rate. Daily attention should be paid to maintaining physical and mental happiness, ensuring balanced intake of nutrients, and so on.