There are many causes of multiple nodules in both lungs, which are roughly divided into four categories, infectious, benign neoplasm, malignant neoplasm, and vascular origin, as follows: 1. Infection: also includes tuberculosis infection, fungal infection, spherical pneumonia, lung abscess, parasites, and other infections. 2. Benign neoplasm: mainly divided into malignant tumor, chondrosarcoma, fibroma, lipoma, etc. 3. Malignant neoplasm: divided into lung cancer, carcinoid tumor, lymphoma, metastatic cancer, etc. 4, lymphoma, metastatic carcinoma, etc. 4, vascular origin: there are arteriovenous malformation, pulmonary infarction, varicose veins or hematoma, etc. The etiology of pulmonary nodules is complex, and it is mainly based on the patient’s symptoms and the imaging description of the nodules to make a comprehensive judgment. If you have a pulmonary nodule, you do not need to be too nervous, and you can go to the respiratory department directly.