A typical normal range is 4.5 to 11.2 micrograms per deciliter (mcg/dL).
Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.
The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.
Greater than normal levels of T4 along with low levels of TSH may be due to conditions that involve an overactive thyroid, including:
Lower than normal levels of T4 may indicate:
AACE Thyroid Task Force. American Association of Clinical Endocrinologists medical guidelines for clinical practice for the evaluation and treatment of hyperthyroidism and hypothyroidism. Endocr Pract. 2002;8(6):457-469.
Ladenson P, Kim M. Thyroid. In: Goldman L and Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders; 2007:chap 244.
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