The thyroid is a gland that is prone to multiple nodules, and nodule-like lesions can occur in several different diseases. Nodules are actually tumor-like swellings that are called nodules because they are smaller. When it is said to be something that grows, people get scared, is it a cancerous tumor? In fact, most nodules are benign and very few are malignant. Therefore, it is important not to be afraid of finding nodules on the thyroid gland and not to let them go. After self-examination and ultrasound examination by a doctor, you can basically identify its benign and malignant nature, so as to achieve the purpose of early detection and treatment of malignant nodules and early reassurance of benign nodules. The screening method is summarized in three steps: first, self-examination (self-examination): see and feel; second, ultrasonography (ultrasonography); third, fine needle biopsy for pathology (biopsy), which is also known as the three hurdles. Nodules can occur in the thyroid gland with the following diseases: a. Nodular goiter This is a diffuse, benign lesion of the thyroid gland with nodules occurring. The disease is due to repeated iodine deficiency and iodine supplementation reversion, which alternates many times, resulting in the formation of multiple nodules. Self-examination: look for bilateral enlargement of the thyroid gland with bulging in front of the neck, which can be asymmetrical on both sides; feel the bulging thyroid gland is tough and soft. Ultrasonography: nodules with high echogenicity, fibrous septal echogenicity between nodules, cystic changes within nodules, and calcified plaques, usually large, single or fused, with diffuse distribution of nodules. A biopsy may be performed to obtain a definitive diagnosis from the pathology. Thyroid adenomas are mostly solitary and originate from the glandular epithelium, and are follicular, papillary, or atypical. It is a benign tumor, but 10-15% can become cancerous, 20% can be accompanied by hyperthyroidism, and the tumor grows slowly. Self-examination: look at the local elevation of a bag; feel the nodule is relatively large, the surface is smooth and soft when pressed. Ultrasonography: A single large mass (nodule) can be seen in the thyroid gland. Echoes of cystic changes can be seen in the mass, and those without cystic changes have higher echogenicity and fibrous echogenicity. A fine-needle biopsy can lead to a definitive diagnosis. This disease should not be taken lightly, and larger ones should be operated. If the mass grows rapidly and the blood flow signal increases, it should be surgically removed as soon as possible. Thyroid cancer is a malignant tumor of the epithelial tissue in the thyroid gland, the cause of which is not fully understood. Self-examination: see bulging nodules in the neck, which grow particularly fast in the short term; feel the nodules in the neck and move with swallowing, hard and not smooth. Ultrasonography: irregular nodules are seen in the thyroid gland, with low echogenicity and may have smaller fine dotted calcifications and attenuated posterior field echogenicity; blood flow signal is abundant, and blood flow in the superior artery on the diseased side can be faster than on the healthy side; lymph nodes in the neck on the diseased side are enlarged, and the ratio of the two diameters is reduced, <0.5, and the parenchyma is thicker and uneven, with some obvious medullary nuclei deviation. A biopsy can give a clear diagnosis. In summary, nodules that are fast growing and hard to the touch; nodules with low echogenicity, small calcifications, irregular blood flow and lymph node enlargement on ultrasound can be considered as thyroid cancer, and fine needle biopsy can clarify the diagnosis if necessary. The nodules are mostly benign. In addition, a nodule in the neck must move with swallowing to be a nodule on the thyroid gland, otherwise it is not related to the thyroid gland. The three levels of screening - self-examination, ultrasound and biopsy - can all lead to an accurate diagnosis of thyroid nodules.