Thyroid Stimulating Hormone (TSH)

Test Code

TSH

Alias/See Also

Thyrotropin, TSH

Preferred Specimen

1.0 mL plasma (0.5 mL minimum)

Transport Container

PST (light green top). Red top and SST also acceptable

Specimen Stability

Room temperature: 1 day, Refrigerated: 7 days, Frozen: 1 month

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

Grossly hemolyzed specimens are unacceptable.

Reference Range

Age	Female	Male
Adult (>18 years):	0.36 – 3.74 µIU/mL	0.36 – 3.74 µIU/mL

Pediatric:
0 – 30 days	0.80 – 10.83	0.64 – 12.75
1 month – 5 years	0.59 – 6.78	0.67 – 5.97
6 – 18 years	0.51 – 4.91	0.52 – 5.08

Clinical Significance

Thyroid stimulating hormone is a glycoprotein secreted by the anterior lobe of the pituitary gland. TSH stimulates the normal thyroid gland to synthesize and secrete thyroxine (T4) and triiodothyronine (T3). Although less sensitive measurements of TSH (or free T4) can be used to diagnose severe, clinically apparent hypo- or hyperthyroidism, only a highly sensitive TSH assay has sufficient clinical sensitivity to detect the minor degrees of thyroxine excess or deficiency associated with early, subclinical phases of hypo- or hyperthyroidism.

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.