Since thyroid fine needle aspiration cytology is so good, you may ask: does everyone with a thyroid nodule need this test? Not really, it depends on whether the condition warrants it. Although the test is very safe, it can still increase the risk of local bleeding in some patients with bleeding disorders, and improper handling may also result in unsatisfactory sampling, risk of local infection, etc. Fine needle aspiration is very necessary if you meet the following conditions: 1. When ultrasound examination suggests a nodule >10 mm in diameter, hypoechoic and substantial; 2. Regardless of the size of the nodule, ultrasound suggests the presence of extracapsular growth of a cystic nodule or metastasis in the lymph nodes of the neck; the patient has a history of childhood or adolescent neck radiation; 3. There are immediate family members with papillary thyroid carcinoma, medullary thyroid carcinoma History of multiple endocrine tumors type 2; 4. History of previous surgery for thyroid cancer; 5. Elevated calcitonin levels in the body; 6. Nodules <10 mm in diameter, but ultrasonography suggests features of malignant lesions such as poorly defined borders, very low echogenicity, microcalcifications in the nodule, blood flow disturbance, nodule aspect ratio >1, etc. Therefore, it is up to the doctor to decide whether to perform a puncture or not, depending on the individual case.