Thyroid test results: What do they indicate

[shailaja100]

Hi,

I have had the following symptoms for some time now; dry skin and hair, sensitivity to cold and lethargy. Hence I got my thyroid test done. The results are:

T3: 67 (Normal range: 60 - 200 ng/dl)

T4: 3.6 (Normal range: 4.5 - 12 ug/dl)

TSH: 1.57 (Normal range: 0.3 - 5.5 u IU/dl)

Any idea what this means? I have normally seen low TSH levels leading to low T3 & T4 levels or normal TSH leading to low T3 & T4. But except for my low T4, everything else looks normal..

[Clutter]

Shailaja100,

Low-normal TSH with FT4 below range indicates secondary or tertiary hypothyroidism (central hypothyroidism) due to insufficient bioactive TSH caused by pituitary dysfunction (secondary hypothyroidism) or hypothalmic dysfunction (tertiary hypothyroidism).

Treatment for central hypothyroidism is Levothyroxine to replace the low T4 hormone. In the UK central hypothyroidism is managed in endocrinology as further investigation may be required to check that sex and growth hormones are not also deficient.