Diagnosis and symptoms of hypothyroidism

Dear Ask The Doctor: I have recently had blood taken and the results came back that my TSH levels are 6.49 and my t4 levels are 19.2.. is this normal or have i possibly got hypothyroid?? if it is hypothyroid, why am i still so thin??

Dear Sarah:The normal reference range of Thyroid Stimulating Hormone (TSH) is 0.4 – 5.0 µIU/L, and of thyroxine (T4) is 5 – 12 g/dL, however laboratories vary slightly in their reference ranges so it is important to know what reference range your own laboratory uses. TSH does exactly as the name suggests it stimulates the thyroid gland to produce thyroxine. Your TSH level is high, which suggests that your thyroid gland is underactive. However your thyroxine level is also high, which does not quite fit with a diagnosis of hypothyroidism.The classical symptoms of hypothyroidism are fatigue and weakness, cold intolerance, weight gain, constipation, dry skin and slowed mental function. I would advise discussing your blood results with your family doctor, with reference to your specific laboratory ranges, to reach the underlying diagnosis.