What does the Total T4 (T4) - T4 blood test mean? Get a free analysis of your blood test now. Here's what you get with our free analysis:
The Total T4 test measures the total amount of thyroxine (T4) hormone in the blood, including both protein-bound and free T4. T4 is produced by the thyroid gland and plays a crucial role in regulating metabolism, growth, and development. This test helps evaluate thyroid function and can be used to diagnose and monitor thyroid disorders such as hypothyroidism and hyperthyroidism. It is often performed alongside other thyroid tests like TSH and Free T4 to provide a comprehensive assessment of thyroid health.
A low Total T4 reading may indicate hypothyroidism, a condition where the thyroid gland is not producing enough thyroid hormone. This can lead to symptoms such as fatigue, weight gain, cold intolerance, and depression. However, low T4 levels can also be caused by certain medications, severe illness, or protein deficiency. Further testing, including Free T4 and TSH, may be necessary to confirm the diagnosis and determine the underlying cause.
A high Total T4 reading may suggest hyperthyroidism, a condition where the thyroid gland is overactive and producing excess thyroid hormone. This can result in symptoms like rapid heart rate, weight loss, anxiety, and heat intolerance. However, elevated T4 levels can also be caused by pregnancy, certain medications, or thyroid hormone replacement therapy. Additional tests, such as Free T4 and TSH, may be required to confirm the diagnosis and identify the specific cause of the elevated T4 levels.