The size of 1.2 cm alone cannot determine the severity of thyroid nodules, which should be evaluated in conjunction with the results of thyroid ultrasound and thyroid puncture biopsy. It is generally believed that the size of thyroid nodules does not help to predict or exclude malignant lesions, but the size of the nodule is an important basis for deciding whether or not to perform a puncture biopsy of the nodule, and is also an important assessment indicator during the follow-up process. The benign or malignant nature of the nodule can be initially assessed by the ultrasound results, including the echogenicity of the nodule, whether the edge of the nodule is clear, whether there is a peritoneum, whether there is calcification in the nodule, whether there is attenuation of echogenicity in the posterior part of the nodule, whether the aspect ratio of the nodule is greater than one, and whether there is a rich blood supply, etc., which need to be determined by a combination of various indexes. If necessary, ultrasound-guided fine-needle aspiration biopsy should be performed to determine the benign or malignant nature of the nodule. Patients with thyroid nodules of 1.2 centimeters are advised to seek prompt medical attention.