According to statistics, more than 300 million people worldwide suffer from thyroid disease, with 50 million patients in China alone, and the incidence of thyroid cancer has increased significantly. According to epidemiological studies in many places, thyroid cancer has become the fastest growing solid cancer in recent years, and in the 2011 Beijing Health White Paper, thyroid cancer rose to the fifth place of malignant tumors in women. In the 2010 Shanghai Malignancy Report, thyroid cancer was ranked fifth among female malignancies, with an incidence rate of 7.74% for women and 2.73% for men. As a near seaside area, thyroid nodules are frequent in Tiantai County, and the number of thyroid cancer patients has increased significantly in recent years. The annual volume of thyroid surgery in our department is nearly 1000 cases, and the scope of consultation and treatment includes: thyroid adenoma, nodular goiter, hyperthyroidism, thyroid cancer, and parathyroid adenoma. According to the follow-up data, the recurrence rate of thyroid cancer patients within 40 years after the initial treatment is about 35%, and 2/3 of them occur within 10 years after the initial treatment. Therefore, it is crucial to avoid recurrence of thyroid cancer within 10 years after surgery, and TSH suppression therapy, i.e. taking Euthyroxine (levothyroxine tablets), is an indispensable part of preventing thyroid cancer recurrence. What is TSH suppression therapy? TSH suppression therapy after thyroid cancer surgery refers to the application of thyroid hormone after surgery to suppress TSH at or below the low limit of normal or even undetectable level, through the suppression of TSH with supraphysiological doses of exogenous thyroxine, thus achieving the purpose of suppressing tumor cell growth, avoiding recurrence and reducing mortality. It is a new concept of treatment. For patients with high risk of thyroid cancer recurrence, the TSH control target is always <0.1mU/L regardless of the risk of TSH suppression therapy, and for patients with high risk of side effects of TSH suppression therapy, TSH should be suppressed to the maximum tolerable range close to the standard, and TSH suppression therapy should be continued for 5-10 years. After 5 to 10 years of disease-free survival, only thyroid hormone replacement therapy (physiological dose, TSH in normal range) TSH suppression therapy needs to be followed up Patients with postoperative thyroid cancer taking long-term eugenol to suppress TSH need to come to the hospital regularly for follow-up after TSH attainment, and also need to monitor the skeletal system and cardiovascular system related conditions. During the dose adjustment phase of levothyroxine tablets, TSH will be measured every 4 weeks or so, and thyroid function will be rechecked every 2-3 months for 1 year, every 3-6 months for 2 years, and every 6-12 months for 5 years after reaching the standard to make sure TSH is maintained in the target range. Prolonged TSH suppression increases the incidence of osteoporosis in postmenopausal women and leads to an increased risk of fracture in perimenopausal women. Serum calcium/phosphorus, 24-hour urine calcium/phosphorus, biochemical markers of bone turnover, and BMD (bone mineral density) measurements are used as appropriate for medical conditions. Prolonged maintenance of TSH at very low levels may increase cardiac load and myocardial ischemia, triggering or exacerbating cardiac rhythm disturbances, causing resting tachycardia, increased myocardial weight, and increased mean arterial pressure. Regular electrocardiogram testing is required, and ambulatory electrocardiogram and echocardiogram are performed when necessary. Regularly monitor blood pressure, blood glucose and lipid levels, and if necessary, determine the carotid intima-media thickness to help assess the risk of atherosclerosis. Precautions for taking Eugenol 1. Take it in the morning on an empty stomach. In case of missed dose, double dose should be taken until all missed dose is made up.2. Patients need to adjust dosage according to TSH level in winter and summer.3. Take with vitamins and tonic at 1 hour interval, with iron-containing, calcium-containing or medication at 2 hours interval; with milk and soy food at 4 hours interval; with choleramide or lipid-lowering resin at 12 hours interval.4. Take about 1 month after the first review dose, and every 2-3 months for the first year after stabilization. The medication should not be stopped numbly during pregnancy, and the medication should be adjusted appropriately according to the different months of pregnancy. 6. Patients with hypertension, diabetes and other cardiovascular diseases need to be tested regularly for blood glucose, blood lipids, blood pressure, electrocardiogram, etc.