Solid nodules in both lungs may be caused by benign lung diseases such as misshapen tumors, which are mostly not serious, or by malignant diseases such as bronchopulmonary cancer, which are more serious. Lung nodules are dense shadows in the lungs detected by chest CT and other imaging tests, of which those <1cm are called small nodules. Lung nodules can be categorized into solid nodules, pure ground-glass nodules, and mixed ground-glass nodules based on their density, with solid nodules having about a 7% risk of malignancy. Solid nodules in both lungs may be caused by benign diseases such as misshapen tumors, sarcoidosis, rheumatoid nodules, or malignant tumors such as bronchopulmonary carcinoma. If they are caused by benign diseases, they can be improved or cured by timely treatment, so they are not serious; if they are caused by malignant tumors such as lung cancer, they may be life-threatening if not treated in time; however, the nodules are relatively small, and most of them are early-stage lung cancers, and the prognosis can be greatly improved after timely surgical treatment. It is suggested that patients should consult the doctor in time, follow the doctor's instruction for further examination, clarify the specific cause of the disease, and treat the disease under the doctor's guidance.