Normal people do not have nodules in their lungs. Nodules in the lungs are round-like changes in the lungs that are found through tests such as lung imaging, including chest radiographs or CT. Nodules in the lungs may indicate certain pathologies. There are many causes of lung nodules, most of which are clinically benign lesions, such as inflammatory reactions. In specific bacterial infections or tuberculosis caused by Mycobacterium tuberculosis, small nodules with varying degrees of fibrosis and calcification in the lungs may remain after the inflammation has healed, manifesting as nodule-like changes in the lungs. It is also important to note that rare malignant tumors of the lung, such as bronchopulmonary cancer, can also cause cancerous nodules in the lungs. If lung nodules are found, the specific cause of lung nodules should be further identified and treated according to the cause. Patients should pay attention to quit smoking and alcohol in daily life.