Thyroid Bloodwork - Secondary Hyperthyroidism?

[CraigyD]

I've recently had some Thyroid blood tests done due to an enlarged right thyroid lobe and intermittent hyper symptoms and these are the results:

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Total Thyroxine (T4) - 127 nmol/L - Range 59 - 154
TSH - 2.16 mIU/L - Range 0.27 - 4.20
Free Thyroxine - 18.9 pmol/L - Range 12.0 - 22.0
Free T3 - 7.2 pmol/L - Range 4.0 - 6.8
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Thyroglobulin Antibody - < 0.9 IU/ml - Range 0 - 4.9 (Negative)
Thyroid Peroxidase Antibodies - 0.9 IU/ml - Range < 9 (Negative)
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TSH Receptor Antibodies - 0.58 U/L - Ranges
Negative - < 1.5 U/l
Borderline - 1.5 - 1.75 U/l
Positive - > 1.75 U/l


Although some of the results are near the upper level of the ranges the only one that stands out is the Free T3 which was over the range.

Has anyone got any thoughts or opinions regarding my results?

Cheers
Craig

[GD Women]

I don't think your T3 is all that high for worry, but certainly worth a watch full eye.

Few thoughts based on that you are not taking thyroid medication or supplements:

Redo T3 test in a few weeks after the first one;

Something could have interfered with level or an error some place in the process.

T3 tends to fall later than T4 in patients developing thyroid failure, and may be even elevated in early hypothyroidism.

T3 is a transient figure, it can change throughout the day and T4 is more commonly used (along with TSH) to figure out exactly what is going on with the thyroid.

T3 scenarios if repeat test is still high:
Central TSH excess - Central hyperthyroidism is a rare condition in which thyrotoxicosis results from primary overproduction of TSH by the pituitary gland with subsequent thyroid enlargement and hyperfunction. The two known causes of central hyperthyroidism are TSH-producing pituitary tumors (TSHomas) and the syndrome of PRTH. Both of these entities are characterized by clinical thyrotoxicosis, diffuse goiters, elevated circulating levels of free T4 and T3, and a nonsuppressed serum TSH ncbi.nlm.nih.gov/pubmed

TSH assay artefact

Thyroid hormone resistance - Thyroid hormone resistance describes a rare syndrome where the thyroid hormone levels are elevated but the thyroid stimulating hormone (TSH) level is not suppressed, or not completely suppressed as would be expected. The most common cause of the syndrome are mutations of the β (beta) form of the thyroid hormone receptor, of which over 100 different mutations have been documented. Mutations in MCT8 and SECISBP2 have also been associated with this condition.

Poor Mitochondrial production of ATP - Can be due to nutrient deficiency, viral damage, or toxic burden.

early sign of recurrence of Graves' hyperthyroidism

congenital goiter - due to defective organification of iodide (TPO defect) or defective synthesis of thyroglobulin.

often seen with TSH-secreting pituitary tumors