Special handling instructions for tsh test
Cleveland Clinic Laboratories
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|
| 1 mL | Plasma | Lithium heparin PST (Lt. Green) | Centrifuge and refrigerate. | Submit in original tube or aliquot into CCL aliquot tube |
Alternate Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|
| 1 mL | Serum | SST (Gold) | Centrifuge and refrigerate. |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|
| 0.5 mL |
Stability
| Environmental Condition | Description |
|---|
| Ambient | 8 days |
| Refrigerated | 14 days |
| Frozen | 24 months |
Days Performed
Turnaround Time
Methodology
| Name | Description |
|---|
| Electro Chemiluminescence Immunoassay (ECLIA) |
Reference Range
Clinical Info
Produced by the anterior pituitary gland, thyroid-stimulating hormone (TSH) stimulates the thyroid gland to convert iodine and the amino acid tyrosine into the thyroid hormones thyroxine (T4) and triiodothyronine (T3), which in turn regulate metabolism, growth, and development. These free thyroid hormones also work in a negative feedback loop to regulate the amount of TSH that is released from the pituitary gland. Testing for TSH is a highly sensitive indicator for hypothyroidism and an important tool in diagnosing thyroid dysfunction. An elevated TSH result usually indicates an underactive thyroid (hypothyroidism), and a decreased TSH result indicates an overactive thyroid (hyperthyroidism) or excessive amounts of thyroid medication in an individual being treated for hypothyroidism. The latest “third-generation” assays for TSH are sensitive enough to distinguish moderately low but still clinically normal levels of TSH from lower levels indicative of hyperthyroidism. If a TSH result is abnormal, free T4 or total T4 can be ordered to confirm diagnosis of hypo- or hyperthyroidism. If diagnosis is still inconclusive, free T3 or total T3 may be ordered.
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