The prevalence of thyroid nodules is very high and there are many different types of nodules. The first step is to visit an endocrinologist who will give you the appropriate tests to determine the nature of the nodules. High resolution ultrasound: High resolution ultrasound has the advantages of non-invasive, non-radioactive and repeatable, and is one of the routine tests. Thyroid function tests: including thyroid stimulating hormone (TSH), free T3, free T4, is one of the most important tests to determine whether the nodule is accompanied by functional abnormalities; the following tests are not routine and are chosen according to each individual’s condition: 1. thyroid nuclear scan: ECT, a special test that shows the location, morphology, intra-glandular lesions and radioactive distribution of the thyroid gland; 2. Other imaging tests such as CT and MRI are valuable in determining the size of the tumor and airway obstruction, and should only be considered when there is a need to check whether the tumor is invading and compressing the adjacent tissues; 3. Thyroglobulin and thyroid peroxidase antibodies are measured when chronic lymphocytic thyroiditis is suspected, calcitonin is used for the diagnosis of medullary carcinoma, and thyroglobulin is used for dynamic follow-up after total thyroidectomy for thyroid cancer.