What does the Free T3 (FT3) - FT3 blood test mean? Get a free analysis of your blood test now. Here's what you get with our free analysis:
Free T3 (FT3) measures the amount of unbound triiodothyronine hormone in the blood. T3 is the active form of thyroid hormone, responsible for regulating metabolism, body temperature, and heart rate. The 'free' portion is not bound to proteins and is thus available for use by the body. This test is important for assessing thyroid function, especially when T4 levels are normal but thyroid dysfunction is still suspected. It's often used in conjunction with other thyroid tests to diagnose and monitor conditions such as hyperthyroidism, hypothyroidism, and to adjust thyroid medication dosages.
A low Free T3 level may indicate:
Low FT3 can lead to symptoms such as fatigue, weight gain, depression, and cold sensitivity. Further testing and clinical evaluation are necessary to determine the underlying cause and appropriate treatment.
An elevated Free T3 level may suggest:
High FT3 can cause symptoms like anxiety, rapid heartbeat, weight loss, and heat intolerance. Additional tests and clinical assessment are crucial to confirm the diagnosis and determine the best course of treatment, which may include antithyroid medications or other interventions.