The tests that can be done to check the lungs include chest CT, bronchoscopy, lung function tests, tumor markers, pathogen tests, etc. 1. Chest CT: Chest CT is the most commonly used means of examination for various organic lung diseases, which can clearly show lung inflammation, tuberculosis, chronic obstructive pulmonary disease, interstitial lung disease and lung tumor. In addition, CT pulmonary arteriography can also clearly diagnose pulmonary embolism and assess the severity of the disease. 2. Bronchoscopy: Bronchoscopy can enter the lungs through the bronchial tubes to directly observe the lung lesions, and it can also take biopsies for pathological examination, which can clearly diagnose lung tumors and so on. 3. Lung function test: at present, the clinical methods of lung function measurement are basically limited to ventilation function and gas exchange function, and the most commonly used is the ventilation function of lungs, including the examination of alveolar air content (i.e., lung volume, or lung volume), the flow rate of the airflow in the airway and its influencing factors, which can indicate whether there is lung ventilation dysfunction. 4. Tumor markers: mainly to assist in the diagnosis of lung tumors. For example, CEA is elevated in some patients with non-small cell lung cancer, and neuron-specific enolase is a more specific tumor marker for small cell lung cancer. 5. Pathogen examination: It is mainly to determine the pathogens of lung infection and guide the use of anti-infective drugs. For example, sputum culture, sputum smear, antacid staining, drug sensitivity test and so on. It is recommended that patients with lung diseases should go to the hospital as soon as possible, choose the best examination method under the guidance of professional doctors according to their conditions, make a clear diagnosis as soon as possible, and be treated accordingly.