The difference between pneumonia and lung cancer: First, the symptoms are different. Pneumonia usually has coughing symptoms, which are relatively short and can be cured after anti-infection treatment; lung cancer has chronic cough, coughing blood, chest pain and other symptoms, and the symptoms cannot be improved after treatment. The imaging manifestations are different. Pneumonia is seen as some thickened texture of the lung; lung cancer is mainly seen as shadow and the size of the tumor is determined according to the condition of lung cancer. Pneumonia is mainly treated with antibiotics or symptomatic treatment; lung cancer is treated with surgery, radiotherapy, chemotherapy and target cell therapy. The prognosis is different. Pneumonia can get better after treatment; lung cancer cannot get better and can affect people’s life.