A thyroid nodule growing 1mm a year is not fast. It could be that there is an error in measurement and there is no actual growth. It is also possible that the thyroid gland is growing slowly. 1. Measurement error: thyroid ultrasound measurement will have a certain degree of error, different machines, its measurement results may be different, there are errors, the same doctor at different times measurement will also have errors, 1mm in the error range, does not have a very great significance, the nodule in the year may not have grown. 2. Slow growth: Whether a thyroid nodule is serious or not after discovery depends mainly on the nature of the thyroid nodule. If a benign lesion is considered, it can be reviewed regularly. If the nodule is relatively large and has pressure symptoms, it can be surgically removed. If there is a chance of malignancy, ultrasound-guided puncture or surgical removal of the nodule together with the surrounding thyroid tissue can be performed to confirm the diagnosis. In conclusion, patients with a history of thyroid nodules should have regular review of thyroid ultrasound, thyroid function and other tests, and under the guidance of the doctor.