2mm is not very serious, it depends on the specific nature, mainly on the ultrasound results, meaning to look at the indications in the thyroid gland to measure whether the tumor is benign or malignant, and if there is calcification or abnormal lymph nodes, consider whether the nodule is dangerous. If it is 2mm, there is a combination of calcification or abnormal lymph nodes, it is only serious if a tumor is suspected, but generally it is not serious. If a single, solid tumor develops in a small child, teenage girl, or young person, any younger age, it is more important to consider if it is malignant. On the contrary, if the nodes are more frequent and they are on the side of adults, not children, the chance of malignancy is relatively small. over 40 years old, if the nodes are more frequent, they may not necessarily be malignant, so you can observe more and consider whether you need surgery, the younger you are, the more attention you should pay.