The presence of high thyroid-stimulating hormone (TSH) may be associated with normal physiologic changes, hypothyroidism, and other conditions, and consultation with a physician is recommended. Due to the effect of hCG, the upper and lower limits of the serum TSH reference range decrease to varying degrees in early pregnancy. Serum TSH gradually rises in mid-pregnancy and may even be higher than in the general population in late pregnancy. High TSH during pregnancy can also be seen in hypothyroidism and subclinical hypothyroidism. If hypothyroidism is considered, it is also necessary to look at the FT4 and TT4 levels; if both are decreased and TSH is elevated, then hypothyroidism is considered. If FT4 and TT4 are normal and TSH is elevated, then consider subclinical hypothyroidism. Based on the patient’s clinical manifestations and relevant laboratory and examination data, the cause of high thyroid stimulating hormone needs to be clarified with the help of the doctor, and targeted treatment or therapy should be carried out.