Hyperthyroidism is hyperthyroidism. Pregnancy hyperthyroidism may be a transient hyperthyroidism caused by elevated HCG levels in pregnancy, i.e. hyperthyroidism in pregnancy syndrome. If symptoms such as proptosis and goiter appear at the same time, the condition is considered to be true hyperthyroidism and should be treated with medication as prescribed by the doctor. Therefore, the causes of hyperthyroidism in pregnancy are different and the treatment is also different.1. Pregnancy hyperthyroid syndrome: HCG and thyroid stimulating hormone TSH have homology. Pregnant women with elevated levels of HCG will have elevated levels of free T3 and free T4, as well as reduced levels of thyroid stimulating hormone, or hyperthyroidism, which is clinically known as pregnancy hyperthyroid syndrome. Pregnant women usually do not have the typical symptoms of hypermetabolism and do not experience significant palpitations or fear of heat in a resting state. In some cases, the elevated thyroid hormone will gradually return to normal with the increase of pregnancy weeks, so it is recommended to observe temporarily and not to take oral anti-thyroid medication for treatment, and pay attention to regular pregnancy checkups. 2. Hyperthyroidism: the process of pregnancy does combine with true hyperthyroidism, or hyperthyroidism appears before pregnancy and is only discovered during pregnancy checkups. In some cases, the symptoms may include elevated basal metabolism at rest, palpitations, fear of heat, etc. Some pregnant women may also have a combination of typical proptosis and goiter. Since radioactive iodine treatment or surgery cannot be applied during pregnancy, oral antithyroid drugs can be used under the guidance of a doctor. Monitor blood and liver functions closely, review thyroid function regularly and adjust the dose of medication, as well as observe any side effects of medication, fetal heartbeat, fetal movement and fetal development. The thyroid function of the newborn and the pregnant woman needs to be assessed after childbirth.