The following nodules are generally considered benign: cystic nodules, where ultrasound may indicate an echogenic or fluid dark area. Mixed or cystic nodules that are predominantly cystic in nature. Specially, the above two types of nodules are benign “calcifications” even if the ultrasound describes dotted strong echogenicity in the nodule, which is called “calcification”. They are usually the result of colloid coagulation. What nodules are likely to be malignant? 1. Solid or predominantly solid mixed nodules with ultrasound suggesting punctiform strong echogenicity or abnormal morphology or a very rich blood supply. 2. Nodules with an ultrasound grading of TI-RADS grade 4 or higher. Specially, if strong echogenic accompanying sound shadows such as masses or arcs or rings or sheets appear within solid nodules, ultrasound suggests coarse calcification. This is also usually a benign calcification. For benign thyroid nodules, the rate of malignancy is only 4% and may result in lifelong hypothyroidism requiring medication or recurrence after surgery. For benign thyroid nodules, the indications for surgery are 1. local pressure symptoms associated with the nodule; 2. combined with hyperthyroidism. 3. The mass is located behind the sternum or in the mediastinum. In other words, if a benign nodule does not compress the trachea and affect breathing, compress the esophagus and affect swallowing, compress the nerves and cause hoarseness, or cause hyperthyroidism that is ineffective with medical treatment, regardless of the size or number of nodules, it can generally be treated conservatively – that is, surgery is not necessary, and regular ultrasound examinations every six months to see if there are any changes can be performed.