Hypothyroidism is a relatively common clinical thyroid disorder, which is mainly caused by chronic lymphocytic thyroiditis, iodine-131 treatment of the thyroid gland, or hypothyroidism after thyroid surgery. Laboratory tests show that the thyroid function tests show significantly elevated levels of thyroid stimulating hormones. Free thyroid hormone and free triiodothyronine levels are low. Regardless of the cause of hypothyroidism give, clinically are given eugenol replacement therapy. This medication is usually taken orally in the morning half an hour before meals on an empty stomach, and the thyroid function is rechecked about once every 4 weeks, and the dosage of Eugenol is adjusted according to the results of the thyroid function until the thyroid function reaches a normal range.