The presence of striated shadows in the lungs may be caused by diseases such as pneumonia, tuberculosis or pleurisy. 1. Pneumonia: If you smoke for a long time or inhale second-hand smoke for a long time, it may lead to inflammatory stimulation of the lungs, and streaks will be found through examination. 2. Tuberculosis: mainly related to infection with Mycobacterium tuberculosis, which is contagious and may be cross-infected if there is prolonged contact with tuberculosis patients. The lung tissue is stimulated by the pathogenic bacteria, and streaks will be found by imaging. 3. Pleurisy: usually developed from chronic bronchitis, repeated stimulation of pleural tissue, causing pleural effusion, through the examination may find the presence of streaks. It is impossible to accurately analyze the etiology of the streaks in the lungs. At present, it is recommended to consult the doctor in time and diagnose and analyze the disease through lung CT and lung puncture biopsy, and once malignant lesions are detected, it is recommended to comply with the doctor’s instructions for treatment.