Description
TSH with Reflex to Free T4 - For differential diagnosis of primary, secondary, and tertiary hypothyroidism. Also useful in screening for hyperthyroidism. This assay allows adjustment of exogenous thyroxine dosage in hypothyroid patients and in patients on suppressive thyroxine therapy for thyroid neoplasia.
Specimen collection after fluorescein dye angiography should be delayed for at least 3 days. For patients on hemodialysis, specimen collection should be delayed for 2 weeks.According to the assay manufacturer Siemens: "Samples containing fluorescein can produce falsely depressed values when tested with the Advia Centaur TSH3 Ultra assay."
TSH blood test is used to help determine overall thyroid function by measuring levels of Thyroid Stimulating Hormone. Thyroid-stimulating hormone (TSH) is produced when the hypothalamus releases a substance called thyrotropin-releasing hormone (TRH). TRH then triggers the pituitary gland to release TSH.TSH stimulates the thyroid to produce thyroxine (T4) and ultimately triiodothyronine (T3). These hormones stimulate the metabolism of nearly every tissue in the body.
The Free T4 test is used to assess thyroid function, indicate hypothyroidism or hyperthyroidism, help diagnose thyroid disease, and evaluate the effectiveness of thyroid treatment.Thyroxine (T4) is one of the two main hormones produced by the thyroid, a butterfly-shaped gland in your throat. Along with the hormone Triiodothyronine (T3), T4 helps regulate how your body stores and uses energy. Thyroxine affects various areas of health, including metabolism, growth, digestion, heart and muscle function, brain development, and bone maintenance.
