Testing Details
Fasting Required: NO
Preferred Specimen: Serum
Limitations: Nonthyroidal chronic diseases, nicotinic acid and nutrition may decrease results. Thyrotoxicosis may not always cause abnormal results. Binding protein variations may cause variations in results. Increases may be associated with pregnancy or oral contraceptive use.
Reference Range(s):
| T4 (Thyroxine), Total | 4.5-12.0 mcg/dL |
| Free T4 Index (T7) | 1.4-3.8 |
Turnaround Time: 3 Days
Test Code: 867
