Most of the multiple nodal metastases in both lungs imply metastasis of malignant tumors, but they may also be caused by inflammation and tuberculosis in the lungs. Specific need to carry out lung CT, lung puncture biopsy and other tests to determine. The specific analysis is as follows: 1. Malignant tumor: tumor cells, due to genetic mutation, have unrestricted growth and can metastasize through blood and lymphatic channels, or directly spread and invade surrounding tissues. Therefore, multiple nodules in both lungs may be primary lung cancer nodules with multiple metastases, or other malignant tumors metastasized to the lungs to form multiple nodules. And the shape of nodules is irregular, the boundary with surrounding is unclear, and the development is faster in a short time. 2. Inflammation: bacteria, viruses, fungi and other pathogens can invade multiple tissues in the lungs, causing inflammation in multiple places, and nodules can be formed after phagocytosis of pathogens by phagocytes and other immune cells, which is manifested as multiple nodules in the lungs. 3. Tuberculosis: when the immunity of the body is low and the toxicity of tuberculosis is high, tuberculosis bacillus can have multiple metastases, resulting in multiple injuries in both lungs, and multiple nodules can be seen in both lungs in the chest radiographs and CT and other imaging examinations. Therefore, when patients find multiple nodule metastasis in both lungs, it is recommended to go to regular hospitals for chest CT, lung puncture biopsy and other examinations in time to clarify the cause of the disease and treat it as early as possible. Don’t avoid medical treatment and make mistakes.