What does it mean to have nodules in the lungs?

Pulmonary nodules can be caused by multiple factors, mainly including: 1. Old lesions: such as pulmonary nodules left after recovery from tuberculosis, which may even be accompanied by nodule calcification. 2. Benign tumors: such as pulmonary hamartomas, which may be caused by genetic factors, abnormal embryonic development, etc. 3. Sarcoidosis or pneumoconiosis: sarcoidosis is a multi-system granulomatous disease of unknown cause, while pneumoconiosis results from excessive inhalation of dust due to occupational factors; both can lead to multiple nodules in the lungs. 4. Malignant lesions: such as early-stage lung cancer or metastatic lung cancer, which can also cause pulmonary nodules. For benign small nodules, a strategy of regular follow-up is generally adopted; for nodules suspected to be malignant, further examination and treatment are required.