High thyroid stimulating hormone during pregnancy is most likely due to hyperthyroidism in pregnancy. During pregnancy, the anterior pituitary gland is gradually enlarged and various micronutrients in the body interact with each other to increase the level of serum estrogen in the body, leading to high thyroid hormone and causing goiter and pregnancy with hyperthyroidism. Patients may experience hypermetabolic syndrome, such as palpitations, increased heart rate, excessive sweating, fear of heat, and gastrointestinal hyperfunction. In severe cases, patients may have a resting pulse rate greater than 100 beats per minute or even have protruding eyes, diffuse goiter, vascular murmurs in the thyroid area, and tremors. Patients diagnosed with hyperthyroidism in pregnancy should rest properly and keep their moods happy, as well as control their diet and take reasonable medication under the guidance of a doctor.