The most common is fever and cough, which are easily misdiagnosed as “cold”. When the chest X-ray or chest X-ray with faint shadow is easily misdiagnosed as “pneumonia”, or “pneumonia” recurring in the same area within a short period of time after conventional treatment is ineffective, we should be vigilant to exclude lung cancer. Chest CT, deep sputum cytology or fiberoptic bronchoscopy should be performed if necessary. Pulmonary shadows are often misdiagnosed as “tuberculosis” and anti-tuberculosis treatment is used without any examination to exclude “tuberculosis”, resulting in delayed diagnosis and treatment with serious consequences. Lung cancer occurring in the apical part of the lung is often accompanied by symptoms such as shoulder pain or limited movement of the upper limbs due to invasion or compression of the surrounding tissues, and is easily misdiagnosed as “frozen shoulder” and delayed. When the chest tightness, shortness of breath, inability to lie down, chest physical examination or imaging examination shows pleural effusion, and the fluid is non-blood exudate, it is easy to misdiagnose as “tuberculous pleurisy”. In this case, pleural fluid should be extracted for cancer cells and tumor markers, and chest CT should be performed after the pleural fluid has been extracted as much as possible to show the lesions in the lung that are hidden by the pleural fluid. If it is suspicious, further examination should be conducted in a specialized hospital. Pain in the lower back, radiating to the buttocks, the lateral side of the lower limbs, or even the lateral side of the calf or foot, and worsening with coughing, stool and other movements that increase abdominal pressure, can be easily misdiagnosed as “sciatica”. Other cases, such as cancerous osteoarthropathy, are easily misdiagnosed as “rheumatic” or “rheumatoid” arthritis because they are often accompanied by joint deformation. Therefore, if the above-mentioned conditions do not work with conventional treatment, you should go to a large general hospital or a specialized hospital in order to exclude lung cancer. If a lump appears on the neck, especially on the clavicle, and increases in size within a short period of time, the patient should immediately go to a large general hospital for consultation. If cancer is suspected, go to a specialized oncology hospital immediately for further examination. Do not receive “anti-tuberculosis” treatment or anti-tumor “test” treatment without any evidence.