TSH
Test Code
899
84443
CPT Code is subject to a Medicare Limited Coverage Policy and may require a signed ABN when ordering.
Clinical Significance
TSH - 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.
Test Resources
Test FAQ
HypogonadismTest FAQ
TSHClinical Focus
Polycystic Ovary Syndrome (PCOS)Clinical Focus
Thyroid Dysfunction in Nonpregnant AdultsTopic Brief
Laboratory Diagnosis of Peripheral NeuropathyTest Summary
Cardiometabolic Disease Assessment (CMDA) PanelTest Details
Methodology
Immunoassay (IA)
Reference Range(s)
| Premature Infants, (28-36 weeks) | |
| 1st week of life | 0.20-27.90 mIU/L |
| Term Infants, (>37 weeks) | |
| serum or cord blood | 1.00-39.00 mIU/L |
| 1-2 days | 3.20-34.60 mIU/L |
| 3-4 days | 0.70-15.40 mIU/L |
| 5 days-4 weeks | 1.70-9.10 mIU/L |
| 1-11 months | 0.80-8.20 mIU/L |
| 1-19 years | 0.50-4.30 mIU/L |
| ≥20 years | 0.40-4.50 mIU/L |
| Pregnancy | |
| First Trimester | 0.26-2.66 mIU/L |
| Second Trimester | 0.55-2.73 mIU/L |
| Third Trimester | 0.43-2.91 mIU/L |
TSH levels decline rapidly during the first week of life in most children, but may remain transiently elevated in a few individuals despite normal free T4 levels. For proper interpretation of an abnormal TSH from a newborn thyroid screen, a Free T4 by Dialysis (test code 35167) or Total T4 (test code 867) should be considered.
Alternative Name(s)
Thyrotropin,3rd Generation TSH,2nd Generation TSH,Highly Sensitive TSH,Thyroid Stimulating Hormone
Preferred Specimen(s)
1 mL serum
Minimum Volume
0.7 mL
Transport Container
Serum separator tube (SST)
Transport Temperature
Room temperature
Specimen Stability
- Room temperature: 7 days
- Refrigerated: 7 days
- Frozen: 28 days
Reject Criteria
Plasma
Setup Schedule
1 mL serum
0.7 mL
Serum separator tube (SST)
Room temperature
Room temperature: 7 days
Refrigerated: 7 days
Frozen: 28 days
Refrigerated: 7 days
Frozen: 28 days
Plasma