Thyroid fine needle aspiration cytology is a technique that has been gradually developed in recent years and has a reliable diagnostic value for most thyroid disorders. In the diagnosis of thyroid disorders, this test is increasingly valued and allows the definitive diagnosis of most thyroid disorders: septic thyroiditis, subacute thyroiditis, Hashimoto’s thyroiditis, Graves’ hyperthyroidism, nodular goiter, papillary thyroid cancer, undifferentiated thyroid cancer, medullary thyroid cancer, and cystic thyroid lesions. In the treatment of thyroid diseases, mainly thyroid cysts and parathyroid cysts can be effectively treated by puncture and aspiration or injection of sclerosing agents, avoiding surgery, which is increasingly popular among patients because it is easy to operate, quick to recover and can be performed on an outpatient basis.