Whether or not a lung nodule disappears depends on the nature of the nodule. 80% of lung nodules are benign. Some benign nodules may remain undeveloped for many years and may even disappear without treatment. 20% are malignant nodules, which may increase in size as the disease progresses. Lung nodules are mainly detected by lung X-ray, CT or MRI. Benign lesions predominate and can be caused by infections with Pneumococcus, Pseudomonas aeruginosa, Klebsiella, etc., as well as Mycobacterium tuberculosis and fungal infections. Non-infectious factors, such as benign lung tumors and malignant lung lesions, can also present as pulmonary nodules. For benign lung nodules due to inflammation, treatment can be directed at the cause. For malignant lung nodules, surgery is preferred, and radiofrequency ablation can also be used.