Serum T4 of 41nmol/L, FT4 of 4pmol/L, TSH of 74mU/L, and Tg positive may be thyroid cancer, thyroiditis, and other diseases. Serum thyroxine T4 is 41 nmol/L, a low concentration; free thyroxine FT4 is 4 pmol/L, a low concentration; thyroid-stimulating hormone TSH is 74 mU/L, a high concentration; and thyroglobulin Tg positivity is an abnormality, while the majority of normal individuals are negative. This manifestation may be due to a variety of diseases such as Hashimoto’s thyroiditis. Among the thyroiditis that may cause the above manifestations are chronic lymphocytic thyroiditis and postpartum thyroiditis. Further investigations such as thyroid ultrasound and thyroid autoantibodies are recommended for the specific cause of the disease. It is recommended to go to the hospital in time if the above mentioned abnormalities occur.