low tsh and t4

[rawalton]

I have been treated for hypothyroidism for 32 years.  My levels are always within normal range until recently.  Now my TSH is .09 and my T4 is .67.  Do you have any idea why both are low?  And, what should I do about it?  The earliest I can get into an endocrinologist is March.  And, I am lucky for that because most only take diabetic patients or none at all.  Otherwise I am a healthy and fit person.
Thanks, Robyn

[Mark Lupo, M.D.]

If you are on a medication that contains T3, then this would be a typical lab profile (but suggestive of over-replacement -- low TSH).  If it is a straight T4 product (ie levothyroxine, synthroid, levoxyl, etc) then this would be suggestive of lab error if your are being treated for primary hypothyroidism and not a pituitary abnormality.

[rawalton]

I take Armour Thyroid. I have taken this for at least 10 years.  I have always had a constant level of TSH and T4 for many years. I have taken the same dosage of 1 g..   My only other symptoms have been fatigue and puffy eye lids( very puffy in the morning).  I am being treated for hypothyroidism and I was diagnosised 30 years ago.  I am now 50.  Healthy weight, practice yoga 6 hrs. a week, walk 30 min. a day, rarely get sick and rarely tired during the day until about a month ago.  Your advice will help me ask the right questions when I do see the endocrinologist.
Thank you for your help.
Robyn