Lung nodules rads3 categories have a 1% to 2% likelihood of malignancy, and are more serious if they are malignant and mostly less serious if they are benign. The LUNG-RADS (Lung Imaging Reporting and Data System) classification of lung nodules assesses the risk of malignancy of lung nodules based on imaging. A category 3 is defined as having a high likelihood of being benign and a malignant risk of 1% to 2%. Category 3 lung nodules are likely to be caused by benign diseases such as lung misshapen tumors, sarcoidosis, pneumonia, etc., which usually can be improved or cured by timely treatment and are not serious; however, there is also a 1%~2% risk of malignant tumors such as bronchopulmonary carcinoma and metastatic carcinoma of the lungs, which are more serious if they are malignant nodules and may affect survival and endanger life. It is recommended that patients with the 3 types of lung nodules consult a specialist and generally require low-dose chest CT after 6 months.