TSH levels higher than 4.5 mU/L usually indicate an underactive thyroid (hypothyroidism), and low TSH levels—below 0.4 ...

Modern-day TSH methods however, with their enhanced sensitivity are also capable of detecting the low TSH values typical of hyperthyroidism. These new methods are often based on non-isotopic ...

Thyroid cancer recurrence risk was not elevated among patients with high-normal vs low-normal exposure to TSH following thyroidectomy.

Historically, the "quality" of a serum TSH method has been determined from a clinical benchmark - the assay's ability to discriminate euthyroid levels (~ 0.4 to 4.0 mIU/L) from the profoundly low ...