Shadows on the lungs are usually abnormalities found during imaging tests, and the diagnosis should be based on clinical symptoms and pathologic tests. 1. Clinical symptoms: Usually, lung shadows are a manifestation of imaging tests, which may be caused by lung infections, and symptoms such as coughing, sputum or chest tightness, shortness of breath, and dyspnea may be present to help confirm the diagnosis. 2. Pathological biopsy: Sometimes further pathological biopsy may be needed to confirm the diagnosis, which may be caused by hyperplastic lesions, benign tumors and lung cancer. The presence of shadows in the lungs should be further examined in the hospital, such as sputum exfoliative cytology, bronchoscopy, sputum examination and serum antibodies, tumor markers, etc., in order to make a clear diagnosis, and then carry out targeted treatment.