Thyroid function tests are a series of blood tests used to measure how well your thyroid gland is working. Available tests include the T3, T3RU, T4, and TSH. The thyroid is a small gland located in the lower-front part of your neck.

SPECIMEN: 3 mL (1.5 mL min.) serum from 1 SST. Ship refrigerated or frozen.

STABILITY: Room: 2 hrs; Refrigerated: 1 week; Frozen: 4 weeks

REPORT: Daily

INSTRUCTIONS: No special preparation required

USAGE: Total thyroid hormone levels include the free as well as the bound form and hence may not reflect the active unbound form of the hormone which is directly related to thyroid dysfunction. Factors affecting the thyroid binding globulin will alter various parameters and may not be a true indicator of primary thyroid disease.