There are two types of high thyroid hormones during pregnancy: transient thyrotoxicosis and hyperthyroidism during pregnancy. Transient thyrotoxicosis requires only symptomatic treatment, while hyperthyroidism is usually treated with oral antithyroid drugs such as propylthiouracil. In early pregnancy, elevated levels of human chorionic gonadotropin can have a mild stimulatory effect on thyroxine receptors, which is manifested by elevated levels of thyroid hormones. Pregnant women may have mild symptoms of hyperthyroidism, clinically characterized as transient hyperthyroidism, which only requires symptomatic treatment and regular rechecks of thyroid function. If the elevated thyroid hormone exceeds the normal range during pregnancy, it belongs to hyperthyroidism during pregnancy. Generally, thiourea drugs, such as propylthiouracil, are chosen for treatment in early pregnancy to control the production of thyroid hormone, and regular rechecks are conducted, and the medication is adjusted under the guidance of the doctor. If high thyroid hormone is found after pregnancy, it is recommended to consult a doctor in time to identify the cause of the disease and intervene as soon as possible under the guidance of the doctor to prevent high thyroid hormone from causing adverse effects on the health of the pregnant woman and the development of the fetus.