Thyroid-Stimulating Hormone (TSH)

Test Code

TSH

Alias/See Also

Epic: LAB129

Preferred Specimen

Specimen Type: Serum
Collection Container: Serum gel
Specimen Volume: 3 mL

Minimum Volume

0.5 mL

(Collection two full microtainers for infants <10 days old)

Other Acceptable Specimens

Specimen Type: Plasma
Collection Container: Green top (Lithium heparin)

Instructions

Centrifuge and separate cells after clot formation and within 4 hours of collection. Remove serum/plasma if testing will be delayed more than 24 hours

Transport Container

Plastic vial

Specimen Stability

Room temperature: Unacceptable
Refrigerated (on gel): 24 hours
Refrigerated (off gel): 7 days
Frozen: 6 months

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Samples stored on gel >24 hours, unlabeled, mislabeled, wrong tube type, hemolyzed, QNS, exceeds specimen stability requirements.

Methodology

Chemiluminescent Micro-particle Immunoassay (CMIA)

Setup Schedule

Daily

Report Available

Same day

Limitations

Heterophile antibodies may cause falsely elevated or depressed results. Potential Interference from hemoglobin, bilirubin triglycerides and protein: Hemoglobin ≤ 500mg/dl, ≤ 20mg/dl, Triglycerides ≤3000mg/dl and Protein ≤ 2 and 12 g/dl.

Reference Range

0.35 - 4.94 IU/mL

Clinical Significance

TSH stimulates the production and secretion of T4 and T3. TSH production and secretion is under the influence of TRH. When TSH methods are ultra-sensitive, they can distinguish between euthyroid and hyperthyroid populations. TSH levels are used as an aid in assessing thyroid status, diagnosis of disease, and treatment of thyroid disease.

Performing Laboratory

Inova Laboratories

2832 Juniper Street

Fairfax, VA 22031

Last Updated: March 9, 2023
Last Review: N. Wolford, March 9, 2023

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.