If a thyroid nodule grows large and forms a diffuse goiter that penetrates deep into the sternum, it may compress the mediastinum and thus the lung tissue. If a malignant thyroid nodule is not detected and treated in time, it may grow gradually and metastasize. In advanced stage, all kinds of malignant tumors will metastasize by leaps and bounds, and malignant tumors of thyroid gland will metastasize to lung foci, forming malignant tumor foci of lung, which is difficult to cure and will affect life and health. Therefore, once a thyroid nodule is found, if there is an indication for surgery, it should be fully and actively treated surgically. Malignant nodules should be detected and treated early, and nodules that are not good or bad in nature can be followed up for a short period of time, and the thyroid ultrasound should be reviewed regularly according to medical advice.