Most people don’t know where the thyroid gland is located, but most people are not unfamiliar with “big neck disease”, which is an enlargement of the thyroid gland, which tells us that the thyroid gland is located in the neck. To be more specific, the thyroid gland is located about 2 to 3 cm below the “laryngeal node” that we can touch ourselves, and can move up and down with it when we swallow something. A thyroid nodule is a lump in the thyroid gland that moves up and down with the thyroid gland as you swallow, and is a common clinical condition that can be caused by a variety of factors. With the development of imaging technology, the detection rate of asymptomatic thyroid nodules is increasing. Thyroid nodules can be divided into solitary and multiple nodules, which vary in size, location, texture, function and their clinical significance. Ultrasound of the thyroid gland is necessary to confirm the diagnosis of thyroid nodules. It can determine the size of the nodule, the presence of cystic changes and cancerous signs. The discovery of a nodule in the thyroid gland can be stressful for the patient, but 90% of nodules are clinically insignificant and benign. The etiology of benign thyroid nodules includes benign adenomas, focal thyroiditis, prominent portions of multinodular goiters, cysts of the thyroid, parathyroid and lingual thyroid glands, hypoplasia of a single lobe of the thyroid gland resulting in hyperplasia of the contralateral lobe, and scarring and hyperplasia of residual thyroid tissue after surgery or iodine 131 treatment. Fine needle aspiration cytology (FNAC) of the thyroid is the most accurate and cost-effective method to diagnose benign thyroid nodules. 90% of FNAC results are consistent with surgical pathology. There is only a 5% false-negative rate and a 5% false-positive rate. The established criteria for initial biopsy are based primarily on the size of the nodule and ultrasound characteristics. When the size is <1 cm, aspiration is not required unless ultrasound shows suspicious features. The American Thyroid Association currently recommends a repeat thyroid ultrasound every 6 to 18 months for benign thyroid nodules; and every 3-5 years thereafter if the nodule size is stable. Today, the natural course of thyroid nodules is not known, and most experts believe that if a nodule progresses significantly, ultrasound and cytology need to be performed again. However, clinicians are unable to provide an evidence-based follow-up program for patients with nodules that are cytologically negative or not suspicious on ultrasound, and there is no reliable way to identify patients who are likely to progress, and the hypothesis that nodule progression increases the chance of malignancy has not been tested. To address these issues, Dr. Durante from Rome, Italy, analyzed 992 patients from 8 thyroid centers and included patients with nodule characteristics: 1-4 asymptomatic, benign nodules on ultrasound or cytology. The 5-year follow-up concluded that: the biological behavior of nodules with cytologically confirmed benign or non-suspicious on ultrasound was stable, most nodules did not show significant growth during the 5-year follow-up period, and thyroid cancer was rare. Therefore, they concluded that a safe follow-up protocol would be to perform a second ultrasound examination 1 year after the initial follow-up and to evaluate it after 5 years in the absence of progression. However, this follow-up strategy is appropriate for patients with a low rate of nodal progression in 85% of cases, and close follow-up is appropriate for younger patients or older obese individuals with multiple nodes and/or larger nodes (>7.5 mm). In conclusion, ultrasound is necessary for the diagnosis of thyroid nodules, and fine needle aspiration cytology can confirm the diagnosis of benign thyroid nodules to some extent, and a follow-up program should be developed for benign nodules according to their condition.