Thyroid nodules are a very common condition, especially among middle-aged women. Thyroid nodules are divided into two categories, benign and malignant, with benign nodules accounting for the majority and malignant nodules for less than 1%. A variety of clinical thyroid disorders, such as thyroid degeneration, inflammation, autoimmunity, and neoplasia, can manifest as nodules. Thyroid nodules can be solitary or multiple. Multiple nodules have a higher incidence than solitary nodules, but solitary nodules have a higher incidence of thyroid cancer. Clinical manifestations (1) Nodular goiter is more common in middle-aged women. In the absence of thyroid hormone in the body, the pituitary gland secretes more TSH. Under the long-term stimulation of this increased TSH, the thyroid gland undergoes repeated or continuous hyperplasia resulting in uneven enlargement and nodule-like changes. There may be bleeding, cystic changes and calcifications within the nodules. The size of the nodules can range from a few millimeters to several centimeters. The main clinical manifestation is an enlarged thyroid gland with multiple nodules of varying sizes on palpation. Patients have few clinical symptoms, usually only anterior neck discomfort, and thyroid function tests are mostly normal. (2) Nodular toxic goiter This disease starts slowly and often occurs in patients who have had a nodular goiter for many years, mostly aged 40-50 years or older, and is more common in women. When the thyroid gland is palpated, a smooth round or oval nodule with clear borders and a hard texture can be found, which moves up and down with swallowing. Thyroid function tests may show elevated thyroid hormone in the blood, and if the nodule is functionally autonomous, a nuclear scan may show a “hot nodule”. (3) Inflammatory nodules There are two types of nodules: infectious and non-infectious, the former being mainly subacute thyroiditis caused by viral infection, while other infections are rare. The latter is mainly caused by autoimmune thyroiditis, mostly seen in middle-aged and young women, the patient’s conscious symptoms are less, the examination can find multiple or single nodules, hard and tough texture, less pressure pain, thyroid function tests show thyroglobulin antibodies and Thyroid function tests often show strong positivity for thyroglobulin and thyroid microsomal antibodies. (4) Thyroid cysts The vast majority of cysts are formed by degenerative changes in goiter nodules or adenomas, containing blood or slightly mixed fluid, with clear borders and a hard texture. In a few patients, the cyst is caused by a congenital thyroglossal cyst or the remnants of the fourth gill slit. (5) Thyroid tumors include benign thyroid tumors, thyroid cancer and metastatic cancer. Ancillary tests (1) Ultrasound examination of the thyroid gland may show solid, cystic or mixed nodules, while a single solid nodule is more likely to be malignant, a mixed nodule is also likely to be malignant, and a simple cystic nodule is less likely to be malignant. (2) The thyroid nucleus scan is divided into “hot nodules” and “cold nodules” according to the ability of the nodules to take up radionuclides. “Hot nodules are functionally autonomous thyroid nodules and are almost always benign. “Cold nodules may be cancerous, but multiple cold nodules are mostly benign adenomas or nodules, and if there is bleeding or cystic changes in the nodule, it may also appear as a cold nodule. (3) X-ray examination of the neck Small or sand-like calcifications on the nodules may be the sand bodies of papillary carcinoma. Large, irregular calcifications can be seen in degenerative nodular goiter or thyroid cancer. If infiltration or deformation is seen in the tracheal image, it is suggestive of a malignant lesion. (4) Fine needle aspiration cytology of the thyroid gland This test is simple and safe and is very helpful in identifying benign and malignant nodules. (5) Determination of thyroid function Functionally autonomous toxic nodules are mostly hyperthyroid, while hyperfunction can be present in the early stages of subacute thyroiditis and thyroid function can be normal, hyper or hypothyroid in chronic lymphocytic thyroiditis. Most of the thyroid nodules caused by the remaining lesions are normal in function. Treatment principles 1, multiple nodules (1) normal or hypothyroidism, can first try a small dose of thyroid hormone treatment, if after treatment, nodules more obvious, should consider surgery. (2) Toxic thyroid nodules should be surgically removed after hyperthyroidism has been controlled. (2) Individual nodules (1) Hot nodules: Those with hyperthyroidism may be considered for surgical treatment. (2) Cold nodules: (1) Children or young men, especially those with past history of neck radiation therapy or nodules that are hard and immobile, with palpable enlarged lymph nodes in the neck, should be treated directly by surgery; (2) Recently appeared nodules with fast growth rate should be considered for surgery.