Specimen Requirements

Title

TSH (THYROID STIMULATING HORMONE)

Specimen Requirement

1 SST/2.0 mL serum. After 30 minutes of clotting, promptly centrifuge and refrigerate serum.

Methodology

Stability

Refrigerated: 1 week; Frozen: 1 month

Reference Range

By Report

Turnaround

1 day

Clinical Use

The ability to quantitate circulating levels of TSH is important in evaluating thyroid function. It is especially useful in the differential diagnosis of primary (thyroid) from secondary (pituitary) and tertiary (hypothalamus) hypothyroidism. In primary hypothyroidism, TSH levels are significantly elevated, while in secondary and tertiary hypothyroidism, TSH levels are low.

Test Code

TSH