Thyroid masses account for about 4% of adults and most are found on physical examination. They are more difficult to identify before surgery. If the mass suddenly increases in size in the short term, in addition to considering adenoma cystic change and bleeding, attention should be paid to exclude the possibility of cancer. Physical examination should be thorough, especially in children and young patients, as the occupancy is prone to malignancy. Ultrasound has low specificity in identifying benign and malignant thyroid. Fine needle aspiration is now widely used, but there is still a 10% false negative rate. For those who have cold nodules on thyroid nuclear scan, they can be reviewed after 3 months of oral thyroxine tablets, and surgery is required if the nodules are enlarged, or if they are smaller or unchanged, they can be taken orally for another 3 months.