Single solid nodule over 1 cm in size; 2. Single solid nodule less than 1 cm but with calcification or abnormal blood flow or enlarged lymph nodes; 3. Single cyst over 2-3 cm; 4. Multiple nodules with the largest nodule over 2 cm or nodules with calcification or abnormal blood flow or enlarged lymph nodes; 5. Thyroid nodule with previous history of neck radiation exposure or treatment; 6. Patients younger than 20 years of age or older than 70 years of age; 8. 7. male patients with thyroid nodules; 8. patients with retrosternal goiter; 9. patients with thyroid nodules that have suddenly increased in size recently; 10. patients with thyroid nodules with pressure, voice changes, swallowing difficulties and irritating cough.