Low thyroglobulin is considered to be related to thyroidectomy and liver disease. Thyroglobulin can be synthesized and secreted by the thyroid gland and the liver. Thyroglobulin will be low when thyroid tissue is destroyed, such as thyroidectomy or complete removal, radioactive¹³¹ iodine treatment, or when liver disease occurs, such as hepatitis or cirrhosis. Thyroglobulin is a macromolecular glycoprotein secreted by the epithelial cells of the thyroid follicles. Most of it is synthesized by the thyroid cells and released into the residual lumen of the thyroid follicles, while a small portion is synthesized by the liver cells. 1. Thyroidectomy or radioactive ¹³¹ iodine therapy: Thyroid cancer patients who have their thyroid gland removed or have part of their thyroid gland removed will have low thyroglobulin, when more of the thyroid gland is removed, the thyroglobulin value will be lower, and if all of the thyroid gland is removed, the value of the thyroglobulin will be even lower. Radioactive ¹³¹ iodine therapy can damage normal thyroid tissue, which can also produce low thyroglobulin. 2. Liver disease: when the patient’s liver disease, such as severe hepatitis, decompensated cirrhosis, chronic active hepatitis and other diseases make the liver function is damaged, the liver synthesis will reduce the phenomenon of low globulin, which may lead to low thyroglobulin. It is recommended that the patient, with the help of the doctor, according to the development of the disease, targeted treatment.