Routine preoperative tests: routine blood tests, blood biochemistry, coagulation function, hepatitis B, syphilis, AIDS, chest X-ray, electrocardiogram, etc. Thyroid surgery-related tests 1. Seven thyroid function tests: To understand whether there is hyper- or hypothyroidism, and to diagnose autoimmune thyroid diseases. 2. Parathyroid hormone: Used to diagnose parathyroid gland lesions and to assist the surgeon in determining possible postoperative hypocalcemia. 3. Tracheal softening test: After removal of the patient’s enlarged thyroid gland, the trachea may lose its support and collapse, leading to breathing difficulties. 4. Laryngoscopic examination of the vocal cords: Hoarseness and low tone may occur after thyroid surgery, and preoperative examination can rule out the possibility of vocal cords caused by their own pathology. Pre-operative imaging of the thyroid gland 1. Ultrasound: It is the preferred method for diagnosing thyroid disease, and can determine the size of the thyroid gland, identify the nature of thyroid swellings, understand the number of nodules, and detect the presence of enlarged lymph nodes in the neck at the same time. Color ultrasound can also determine the benignity and malignancy of the lesion based on the blood flow in the thyroid gland. 2.CT enhancement + 3D reconstruction: This is the first test in China that can show the morphological changes of the thyroid gland and identify enlarged lymph nodes. The good 3D imaging can also show the distribution and diameter of each blood vessel in the thyroid gland, and localize the thyroid swelling in three dimensions, providing a reliable basis for the doctor to make a surgical plan. 3.Nuclear static imaging: After taking 131 iodine orally, the thyroid gland is scanned and the nature of the lesion is judged according to its “cold, cool, warm or hot” appearance. In addition, the clinician will decide whether to do other auxiliary tests, such as thyroid puncture biopsy and thyroid MRI scan, according to the patient’s specific condition.