Free Triiodothyronine Index (FT3I)

The free triiodothyronine index is one of the thyroid function tests, which is commonly measured by radioimmunoassay. A hormone synthesized and secreted by thyroid follicular cells. FT3 accounts for about 0.3% of T3. It can enter the tissue cells through the cell membrane and exert physiological effects. Its concentration is consistent with the concentration of triiodothyronine in the tissue, and it is also consistent with the metabolic state of the body. It also has diagnostic value for non-thyroid diseases. Clinically, the RIA method is commonly used. Basic Information Specialist classification: growth and development examination classification: blood examination Applicable gender: whether men and women apply fasting: fasting Analysis results: Below normal: Seen in hypothyroidism. Normal value: FT3I: 46.75-21.55 Above normal: Found in hyperthyroidism, the use of thyroid hormone, heparin and other drugs. negative: Positive: Tips: Stop eating iodine-rich foods before checking. Normal value FT4I: 5.45~12.8 (8.09±1.6) FT3I: 46.75~21.55 (126.25±36.08) Clinical significance (1) Elevated in hyperthyroidism, application of thyroid hormone, heparin and other drugs. (2) Reduced in thyroid dysfunction. Low results may be diseases: hypothyroidism, hyperthyroidism results may be high disease: hyperthyroidism considerations 1. Before the inspection, you must stop eating foods rich in iodine, such as kelp, seaweed, sea fish and shrimp, etc., depending on the amount of food, stop eating for 2 to 4 weeks. 2. The following drugs should be stopped before the examination. According to the dosage and time, stop taking 2~8 weeks. (1), iodine-containing drugs, such as iodide, compound iodine solution, iodine-containing tablets, etc. (2) Drugs that affect thyroid function, such as thyroid tablets and antithyroid drugs. (3) Some Chinese herbal medicines, such as seaweed, kelp, fritillary, burdock, Mutong, etc. 3. The patient should be fasted on the day of the examination. 4, venous blood 2ml, not anticoagulation, separation of serum for determination. Inspection process Radioimmunoassay. Not suitable for the crowd People with reduced hematopoietic function such as leukemia, various anemia, myelodysplastic syndrome, or people with thrombocytopenia should pay attention to blood draw, and should not take more or more blood. Adverse reactions and risks 1. After the blood is drawn, do not press the needle hole to avoid subcutaneous hematoma. If there is a small piece of bruise in the blood, it is slightly tender, please don't panic, you can do hot compress after 24 hours to promote the absorption of blood. The general small amount of congestion will gradually absorb in 3 to 5 days and the color will become lighter and return to normal. 2. After the blood draw, symptoms such as dizziness, vertigo, fatigue, etc. should be immediately supine, drink a small amount of syrup, and then undergo a physical examination after the symptoms are relieved.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.