Thyroid Function Test
Protocols
Normal Value:
T3 Total
- Cord blood (>37 weks) = 5 to 141 ng/dL
- 1 to 3 days = 100 to 740 ng/dL
- 1 to 11 months = 105 to 245
- Children
- 1 -5 years = 105 to 269 ng/dL
- 6 to 10 years = 94 to 241 ng/dL
- 16 to 20 years = 80 to 210 ng/dL
- Adult
- 20 to 50 years = 70 to 204 ng/dL
- 50 to 90 years = 40 to 181 ng/dL
- Pregnancy
- Last 5 months = 116 to 247 ng/dL
- To convert into SI unit x 0.0154 = nmol/L
- Last 5 months = 116 to 247 ng/dL
Thyroid Function In Hypothyroidism:
| Causes | TSH | T3 | T4 |
| Pituitary abnormality | High | Low | Low |
| Hashimoto’s disease in an early stage | High | Low | Low |
| Hashimoto’s disease in late-stage | High | Low or normal | Low or normal |
Thyroid Functions In Hyperthyroidism:
| Causes | TSH | T3 | T4 |
| Grave’s Disease | Low | Raised | Raised |
| Thyroiditis with hyperthyroidism | Low | Raised | Raised |
| Thyroid nodule (hot or toxic ) | Low | Raised | Raised |
Thyroid Function Tests Summary:
| Disease | T3 | T4 (total) | T4 free | TSH | Cholesterol |
| Hypothyroidism | decreased | decreased | low | increased | increased |
| Hyperthyroidism | increased | increased | increased | decreased or absent | decreased |
| Excess Thyroid binding globulin (TBG) | increased | increased | Normal | decreased | |
| Decreased thyroglobulin (TBG) | Low | Low | Normal |
Normal Value:
T4 Total (T4)
| Age | µg/dL |
| 1 to 3 days | 11.22 |
| 1 to 2 weeks | 10 to 16 |
| 1 o 12 months | 8 to 16 |
| 1 to 5 years | 7 to 15 |
| 5to 10 years | 6 to 13 |
| 10 to 15 years | 5 to 12 |
| Adult | Male 4 to 12 Female 5 to 12 |
| >60 years | 5 to 11 |
T4 Free
- Newborn (0 to 4 days) = 2 to 6 ng/dL (26 to 77 pmol/L)
- Child 2 weeks to 20 years = 0.8 to 2.0 ng//dL
- Adult = 0.8 to 2.8 ng/dL (10 to 36 pmol/L)
Thyroid Function In Hypothyroidism:
| Causes | TSH | T3 | T4 |
| Pituitary abnormality | High | Low | Low |
| Hashimoto’s disease in an early stage | High | Low | Low |
| Hashimoto’s disease in late-stage | High | Low or normal | Low or normal |
Thyroid Functions In Hyperthyroidism:
| Causes | TSH | T3 | T4 |
| Grave’s Disease | Low | Raised | Raised |
| Thyroiditis with hyperthyroidism | Low | Raised | Raised |
| Thyroid nodule (hot or toxic ) | Low | Raised | Raised |
Table showing lab. test in Thyroid diseases:
| Disease | TSH | T4 |
|---|---|---|
| Multinodular goiter | low | high |
| Single toxic nodule | low | normal or high |
| Subacute thyroiditis | low | high |
| Autoimmune thyroid disease | low | high |
| TRH pituitary adenoma | normal or high | high |
| Gestational neoplasm | low | high |
| Postpartum hyperthyroidism | low | high |
| Hyperemesis gravidarum | low or normal | high |
| Metastatic thyroid cancer | low | high |
| Iodine-induced | variable | high |
| Exogenous thyroxine | low | high |
Thyroid Function Tests Summary:
| Disease | T3 | T4 (total) | T4 free | TSH | Cholesterol |
| Hypothyroidism | decreased | decreased | low | increased | increased |
| Hyperthyroidism | increased | increased | increased | decreased or absent | decreased |
| Excess Thyroid binding globulin (TBG) | increased | increased | Normal | decreased | |
| Decreased thyroglobulin (TBG) | Low | Low | Normal |
Normal value:
TSH
| Age | µU/mL |
Premature infants 28 to 36 weeks gestation | 0.7 to 27 |
| 1 to 4 days | 1.0 to 39 |
| 2 to 20 weeks | 1.7 to 9.1 |
| 5 months to 20 years | 0.7 to 6.4 |
| Adults | |
| 21 to 54 years | 0.4 to 4.2 |
| 55 to 87 years | 0.5 to 8.9 |
| Pregnancy | |
| First trimester | 0.3 to 4.5 |
| Second trimester | 0.5 to 4.6 |
| Third trimester | 0.8 to 5.2 |
- To converts into SI unit x 1.0 = mU/L
Thyroid Function In Hypothyroidism:
| Causes | TSH | T3 | T4 |
| Pituitary abnormality | High | Low | Low |
| Hashimoto’s disease in an early stage | High | Low | Low |
| Hashimoto’s disease in late-stage | High | Low or normal | Low or normal |
Thyroid Functions In Hyperthyroidism:
| Causes | TSH | T3 | T4 |
| Grave’s Disease | Low | Raised | Raised |
| Thyroiditis with hyperthyroidism | Low | Raised | Raised |
| Thyroid nodule (hot or toxic ) | Low | Raised | Raised |
Table showing lab. test in Thyroid diseases:
| Disease | TSH | T4 |
|---|---|---|
| Multinodular goiter | low | high |
| Single toxic nodule | low | normal or high |
| Subacute thyroiditis | low | high |
| Autoimmune thyroid disease | low | high |
| TRH pituitary adenoma | normal or high | high |
| Gestational neoplasm | low | high |
| Postpartum hyperthyroidism | low | high |
| Hyperemesis gravidarum | low or normal | high |
| Metastatic thyroid cancer | low | high |
| Iodine-induced | variable | high |
| Exogenous thyroxine | low | high |
Thyroid Function Tests Summary:
| Disease | T3 | T4 (total) | T4 free | TSH | Cholesterol |
| Hypothyroidism | decreased | decreased | low | increased | increased |
| Hyperthyroidism | increased | increased | increased | decreased or absent | decreased |
| Excess Thyroid binding globulin (TBG) | increased | increased | Normal | decreased | |
| Decreased thyroglobulin (TBG) | Low | Low | Normal |