Low free thyroxine suggests the possibility of hypothyroidism, which needs to be analyzed in combination with clinical symptoms and other thyroid-related hormone indicators, such as thyrotropin.
Free thyroxine, also known as FT4, is a physiologically active form of thyroid hormone, and because it is not affected by serum thyroglobulin, it can more directly reflect the function of the thyroid gland, with higher specificity and sensitivity than total thyroxine.
Patients with hypothyroidism may have symptoms such as chills, fatigue, constipation, swelling of the hands and feet, drowsiness, and some elevation of thyrotropin levels.
It is recommended to go to the hospital in case of low free thyroxine and ask the doctor to make a judgment based on the individual’s condition to determine the cause of the disease.