On May 13, 2015, at the American Association of Clinical Endocrinologists, Professor Bryan R. Haugen from the University of Colorado School of Medicine presented an interpretation of the 2015 American Thyroid Association guidelines for the diagnosis and treatment of thyroid nodules and differentiated thyroid cancer. He focused on epidemiologic data, guideline revisions, and patient-based revisions. Epidemiological Evidence of Thyroid Cancer In July 2014, a set of epidemiological data published in Cancer Research showed that the incidence of thyroid cancer is increasing year by year, and it is expected to rise to the second place of malignant tumors in women and the third place of malignant tumors in men by 2030. And the diagnosis and treatment of thyroid cancer brings a huge financial burden to patients, 4.6% of all tumor patients are bankrupt due to thyroid cancer. Compared with the 2009 guidelines for the diagnosis and treatment of thyroid nodules and differentiated thyroid cancer, the 2015 guidelines are more informative and detailed, in addition to adopting the American College of Physicians (ACP) adapted system for guideline recommendation levels. 2015 guidelines are aimed at evidence-based medicine and clinical guidelines. Compared with the 2009 guidelines, there is a significant increase in recommended items, references, and charts, and the content is richer. (1) Ultrasound diagnosis of thyroid nodules: The guidelines recommend classifying ultrasound diagnosis into 5 levels, which are highly suspicious (malignancy 70%-90%), moderately suspicious (malignancy 10%-20%), low suspicion (malignancy 5%-10%), very low suspicion (malignancy <3%), and benign (malignancy <1%). (2) Ultrasound-guided fine-needle aspiration cytology (FNA) of thyroid nodules: Diagnostic FNA is recommended according to ultrasound features and is classified into 6 levels. (3) Recommended follow-up for thyroid nodules that do not meet the diagnosis of FNA: follow-up thyroid ultrasound is recommended for 6 to 12 months, 12 to 24 months, ≥24 months, and longer, depending on the level of suspicion. (4) A new recommendation was added to the 2015 guidelines: pathology reports should include AJCC/TNM criteria, vascular invasion and number of invading vessels, number of lymph nodes, size of the largest metastatic lymph node, and extra-lymph node invasion. (5) The guidelines classify thyroid cancer into low risk of recurrence, intermediate risk of recurrence and high risk of recurrence according to the stage of differentiated thyroid cancer. (6) Radioactive iodine (RAI) ablation/adjuvant therapy: Postoperative radioactive iodine ablation therapy is recommended based on tumor stage and risk of recurrence. (7) The guidelines recommend human recombinant thyrotropin (rhTSH) for thyroid cancer with low to intermediate risk of recurrence, but not for thyroid cancer patients with high risk of recurrence. (8) The guidelines recommend that response to treatment be determined by levels of suppressive thyroglobulin, stimulating thyroglobulin, thyroglobulin antibodies, and neck imaging.