Serum calcitonin is a hormone secreted by thyroid follicular cells that, when elevated for some reason, increases the excretion of calcium by the kidneys and lowers blood calcium concentrations. Endemic goiter is a type of goiter. In the early stages, there are no obvious clinical symptoms. The thyroid gland is mildly to moderately diffusely enlarged, soft and painless. Very few significantly enlarged cases may show symptoms of pressure, such as dyspnea, dysphagia, hoarseness, and irritating cough. A retrosternal goiter may have symptoms of esophageal or superior vena cava compression. So, what should be done to prevent increased serum calcitonin levels? The following is a brief introduction: Prevention of increased serum calcitonin levels should be the main focus. In areas where endemic goiter is prevalent, salt should be iodized by adding potassium iodide or potassium iodate to the salt. Eating more iodine-rich foods will be sufficient. Treatment depends mainly on the cause: 1. During the physiological period, most goiters are not significant and generally do not need special treatment, most can disappear on their own, but for those with significant enlargement or nodule formation are to be treated. 2, is caused by the intake of food and drugs containing substances that cause goiter. It usually disappears after stopping the medication. Lobectomy of the thyroid gland is a more reasonable and clean surgical procedure. Frozen sections at the time of surgery can be followed regularly if differentiated thyroid cancer is confirmed as long as there are no enlarged lymph nodes in the neck on exploration, which will not cause medical dissemination of cancer cells. It is also possible to completely remove adenomas that are clinically thought to be solitary but are actually multiple, avoiding reoperation for adenoma recurrence.