The TSH has been declining in pregnancy, suggesting the possibility of hyperthyroidism. If it is a transient hyperthyroidism in pregnancy, you can first observe and follow up, symptomatic treatment, if it is a primary hyperthyroidism, you need to carry out active medication to improve the symptoms, and in severe cases, feasible surgical treatment. Transient hyperthyroidism, due to HCG stimulation, symptomatic treatment, usually without drugs, observation and follow-up, with the development of pregnancy HCG levels will gradually decrease, thyroid hormones will slowly return to normal, symptoms will disappear, TSH levels will return to normal. In other cases of primary or secondary hyperthyroidism, antithyroid medications such as methimazole and propylthiouracil should be used according to the week of pregnancy and under the guidance of the doctor. Surgical treatment is usually in the fourth to sixth month of pregnancy, surgical removal of patients in the clinic is rare, easy to miscarry the situation. There is no need to be overly nervous when hyperthyroidism occurs during pregnancy, you need to consult a doctor in a timely manner to clarify the cause of the disease, actively treat the disease under the guidance of the doctor, and regularly review the situation to prevent it from worsening and affecting the fetus. In addition, a drop in TSH during pregnancy may also be caused by other reasons.