If a pregnant woman has high free thyroxine, first of all, she needs to go to the hospital to improve the hormone examination and then make targeted treatment according to the cause. Secondly, high free thyroxine in pregnant women may be caused by the specificity of pregnancy, as the hormonal fluctuations in women’s bodies during pregnancy can easily lead to endocrine disorders, which can easily detect high free thyroxine in humans. In addition, high free thyroxine in pregnant women may be caused by hyperthyroidism. If pregnant women have high free thyroxine, they should not only prohibit the intake of iodine in their diet, but also take appropriate thyroid medications for treatment. However, it should be noted that methimazole is not suitable for use during pregnancy, while propylthiouracil can be taken during pregnancy.