Free T3
Sample: Serum 0.5 mL
Status: Accredited
Schedule: Daily
Units: pg/mL
Range: (See table below)
Remarks: The Thyroid gland has a complex pattern of control. The pituitary gland sends thyroid stimulating hormone (TSH) to the thyroid telling it to produce thyroxin (T4). T4 has its own critical functions within the body but equally important is that some of the T4 needs to convert to T3. Studies are showing that thyroid problems in aging adults is not so much a failure of the thyroid to produce T4 as had previously been thought, rather it is a problem of T4 not converting to T3.
A few symptoms of hypothyroidism:
- Low energy -- fatigue
- Weight gain
- Water retention
- Hair loss (a major cause)
- Dry skin and brittle nails
- Feeling cold in normal temperatures
- Anxiety and irritability
- Depression
- High cholesterol
- Mental fogginess
Free T3 (pg/mL)
| Age | Boys | Girls |
| 1 - 7 d | 1,7 - 9,2 | 1,9 - 14,8 |
| 8 - 15 d | 2,0 - 9,8 | 2,0 - 5,6 |
| 1 - 3 y | 1,9 - 4,9 | 2,3 - 5,4 |
| 4 - 6 y | 1,6 - 6,0 | 3,0 - 6,4 |
| 7 - 8 y | 2,6 - 6,8 | 2,6 - 7,5 |
| 9 - 10 y | 2,1 - 14,9 | 1,3 - 11,2 |
| 11 y | 2,3 - 5,2 | 2,2 - 4,7 |
| 12 y | 2,5 - 4,6 | 2,6 - 4,1 |
| 13 y | 2,6 - 4,7 | 2,5 - 5,2 |
| 14 y | 2,8 - 5,0 | 2,8 - 5,2 |
| 15 y | 2,3 - 4,6 | 2,4 - 4,2 |
| 16 y | 2,4 - 5,0 | 2,5 - 3,9 |
| 17 y | 2,1 - 4,2 | 2,0 - 4,4 |
| 18 - 19 | 2,0 - 4,1 | 2,5 - 6,2 |
