Every year, various units and companies organize physical examinations for their employees, and many of them are found to have thyroid nodules, and the ultrasound results indicate that the nodules are calcified. Mr. Zhang was also found to have calcified nodules in his physical examination this year, and he wondered if the nodules were calcified because of the recent stress. In this era of rapidly increasing cancer incidence, is calcification of nodules a precancerous lesion? Should it be treated or not? A series of questions made Mr. Zhang restless and he decided to seek help from the hospital. There are different types of calcification, and tiny calcifications should be beware of. First let’s understand thyroid calcification. Thyroid calcification refers to the presence of calcium deposits within the thyroid nodules. Calcification is a product of tissue metabolism: deposits of calcium salts, which can occur in both normal glandular tissue and tumor lesions. Different forms of calcification have different meanings and are distinguished by size and diameter: microcalcifications, <2mm in diameter; coarse calcifications, >2mm in diameter; in addition to these two categories there are also marginal calcifications. Calcification of thyroid nodules does not necessarily mean “thyroid cancer”, but there are benign and malignant calcified nodules, among which microcalcifications are more likely to indicate thyroid cancer. Therefore, nodules with microcalcifications should be detected with caution. Besides, to evaluate whether a nodule is malignant, we need to consider the size, nature, single or multiple nodules, location, and whether the boundary is clear, whether there are adhesions, internal blood flow of the nodule, etc. Most cases of malignant nodules are single, poorly defined, irregularly shaped nodules with abundant blood flow signals. Which nodules require surgery? Important factors that influence whether a nodule requires surgery are the size of the nodule, the presence of symptoms due to pressure affecting the whistle tract, and the benignity or malignancy of the nodule. For benign nodules, surgery is not recommended for nodules smaller than 2 cm, just watch the nodules for enlargement; surgery is recommended for nodules larger than 4 cm, and elective surgery is recommended for nodules between 2 and 100 px. Malignant nodules (thyroid cancer) basically require surgery. If the nodule has symptoms of pressure and affects the whistle, surgery is necessary regardless of the benign or malignant nature.