Pneumonia and lung cancer are both relatively common diseases in the lungs, but there is a difference between the two, mainly due to the inconsistency of clinical symptoms, examination results and treatment programs. 1. Inconsistent clinical symptoms: pneumonia mainly manifests symptoms of cough and fever, and some patients with poor control may cough up yellow sputum; lung cancer mainly manifests symptoms of irritating dry cough, coughing up blood, chest pain and low-grade fever. 2. Inconsistent examination results: through lung CT examination, pneumonia mainly manifests as patchy high-density shadow, part of which can be accompanied by solid changes, and the laboratory examination mainly manifests the rise of white blood cells and C-reactive protein; lung cancer mainly manifests as soft tissue mass, which can invade the surrounding tissues, and the blood sampling and laboratory examination can find the rise of tumor markers. 3. Inconsistency of treatment plans: pneumonia is mainly treated with regular application of anti-inflammatory drugs, bacterial infection can be treated with moxifloxacin and so on, mycoplasma infection can be treated with azithromycin and so on; the treatment of lung cancer is mainly to choose radical resection through surgery, and in addition can be assisted by radiotherapy and chemotherapy. If there are obvious cough, chest pain and decline in health condition, it is necessary to consult a doctor in time to diagnose the specific condition and then carry out standardized treatment under the guidance of clinicians.