TSH with Free T4 Reflex

Abbrev Code:TSHR   
Order Code:LAB3795Order Name:TSH with FreeT4 Reflex
Synonyms:Thyrotropin, TSH Reflex
Methodology:Roche: Electrochemiluminescence immunoassay (ECLIA)
Woodwinds: CMIA
CPT Codes: 84443 x1, 84443 x1
Turnaround Time:Varies by site.
Associated Links:

Roche Go Live Schedule

Collection Instructions

Optimal Volume:2.5 mL
Minimum\Peds Volume:0.6 mL
Collection Instructions:Chemistry Tests Containers Chart
Contraindications:Large doses of biotin (10 mg or more per day) may cause clinically significant interference in TSH levels. If interference is suspected, it is strongly recommended that biotin is discontinued for at least one week prior to retesting.

Processing and Shipping

Specimen Processing:Centrifuge and aliquot 1.25 mL, 0.2 mL minimum. Store in refrigerator.
Shipping Instructions:Ship at refrigerated temperature.
Stability:Roche: 8 days at room temperature; 14 days refrigerated; 24 months frozen. Freeze only once.
Test Performed at or Referral Lab Chemistry  (Roche-CSC Maple Grove, Roche-Grand Itasca, Roche-Lakes, Roche-Northland, Roche-Range, Roche-Ridges, Roche-Southdale, Roche-St. John's, Roche-UMMC East, Roche-UMMC West, Woodwinds)


Reference Range:
Age TSH (M/F) FT4 (M/F)
0-7 d 3.2-21.0 mIU/L 0.7-1.8 ng/dL
7 d & older 0.3-5.0 mIU/L 0.7-1.8 ng/dL
0-5 d 0.7-15.2 0.9-2.5
6 d - 2 mo 0.7-11.0 0.9-2.2
3-12 mo 0.7-8.4 0.9-2.0
1-5 y 0.7-6.0 1.0-1.8
6-10 y 0.6-4.8 1.0-1.7
11-19 y 0.5-4.3 1.0-1.6
20 y & older 0.3-4.2 0.9-1.7


Patients Without Pituitary Disease









< 0.4










Suspect hyperthyroid


No metabolic thyroid disease


Suspect hypothyroid






Free T4


No further testing


Free T4







Thyroid gland function testing is based upon the normal response of the pituitary gland to decreased or increased levels of thyroid hormones, principally triidothyronine (T3) and thyroxine (T4). Pituitary and/or hypothalamic hypothyroidism may not be detected through this algorithmic approach and requires both TSH as well as FT4 measurements.


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