Clinical manifestations of mediastinal lung cancer include hoarseness, edema of upper limbs, varicose veins of chest wall and headache. Mediastinal lung cancer means that the cancer cells of lung cancer have caused invasion to the mediastinum. Usually, the main clinical manifestation of mediastinal lung cancer is hoarseness, which indicates that the recurrent laryngeal nerve is obviously compressed, resulting in paralysis of vocal cords. Besides, mediastinal lung cancer will also compress the superior vena cava, resulting in obstruction of venous return, which in turn will cause superior vena cava obstruction syndrome. As a result, patients will have symptoms such as edema of upper limbs, neck and face, varicose veins of chest wall, etc. When further edema is caused to the brain, patients will have symptoms such as headache, drowsiness and blurred vision. When mediastinal lung cancer occurs, it is usually considered that the disease has developed to middle or late stage, and the cancer cells will also metastasize to lymph nodes outside the lungs, liver, pleura, etc. In a word, when patients develop the above symptoms, they may have headache, drowsiness and blurred vision. All in all, when patients are diagnosed with mediastinal lung cancer with the above symptoms, they should actively cooperate with doctors to carry out standardized treatment and strengthen daily life management.