Whether a patient’s thyroid nodule 0.5×0.4cm is serious or not depends on the nature of the thyroid nodule for an objective analysis. First, if the patient’s thyroid nodule is examined by ultrasound and no nodule with blood flow signal, calcification, aspect ratio greater than 1 and other symptoms are found, the nodule in this case is mostly considered a benign lesion and does not require fine needle aspiration or surgical treatment, and the patient’s condition is not serious. Secondly, if the patient has a small thyroid nodule, but it is accompanied by malignant signs such as obvious blood flow signal, calcification foci, aspect ratio greater than 1, unclear border and uneven echogenicity, the patient is highly suspected to have cancerous thyroid nodules and needs to undergo thyroid surgery as soon as possible, and after surgery, the patient may have complications such as incisional infection, fat liquefaction, hoarseness and low calcium convulsions, and the patient’s condition is more serious at this time. .