Thyroid shrinkage is usually not recoverable. There are two reasons for thyroid shrinkage: one is congenital developmental abnormality; the other is caused by atrophy of the thyroid gland later in life. Therefore, shrinkage of the thyroid gland should be detected in time and relevant examinations should be done, such as thyroid function and thyroid ultrasound examination, if the thyroid function and thyroid ultrasound are normal, the shrinkage of the thyroid gland can be reviewed periodically. If the thyroid function and thyroid ultrasound are normal, the shrunken thyroid gland can be reviewed regularly. If the shrunken thyroid gland has thyroid function abnormality, for example, the thyroid hormone secretion is reduced and hypothyroidism occurs, thyroid hormone replacement therapy should be applied at this time, and the clinically selected drug is levothyroxine sodium tablets. The shrunken thyroid gland cannot be restored under a combination of medication and prophylaxis, but it can be prevented from shrinking further and causing more serious lesions.