The mass shadow seen in the upper lobe of the left lung may be pneumonia, lung tumor, tuberculosis and other diseases. It is recommended that the patient can improve the blood routine, sputum culture, chest CT, tumor marker test and other tests to clarify the diagnosis. A mass shadow in the upper lobe of the left lung is usually a mass shadow in the upper lobe of the left lung seen on chest X-ray. It may be related to pneumonia, lung tumor, tuberculosis and other diseases. It is recommended that the patient can complete the following tests to clarify the diagnosis: 1. blood routine: it can detect whether the white blood cells in the blood are elevated, whether there is bacterial or viral infection, etc. 2. Sputum culture: to detect the presence of pneumonia-causing bacteria or Mycobacterium tuberculosis in sputum. 3. Chest CT: with higher resolution, it can detect small lung lesions and parts of the lung that are difficult to be shown by ordinary X-ray chest radiographs, and it can also be used for the clinical staging of lung cancer. 4. Bronchoscopy: it can be used for suspected lung cancer cases should routinely undergo bronchoscopy, whose main purpose is to observe the lesions of trachea and bronchus. It is suggested that patients should go to the hospital in time to improve the examination and clarify the cause of the disease.