Thank you for your query at Doctorspring.com
From your description, you have AutoImmune Thyroid disease (Hashimoto's thyroiditis) which started initially as a subclinical, milder hypothyroidism and over a period has led to almost complete loss of thyroid function, and thats why this high TSH. Your requirement of thyroxine is not met by 50mcg, hence the TSH remains high. Take 100mcg daily, and retest after 2 months. you may have to increase or decrease the dose based on TSH report then. The idea is to keep the TSH in normal range. Thats adequate dose. and this is likely to require lifelong thyroxine supplementation
Feel free to discuss further,
Patient replied :
Thank you for the response. I do have 2 follow up questions.
1) Post 2 months of taking 100 mcg if TSH is lower than range and FT3, FT4 are higher than range then I should reduce Thyroxine to 75 mcg? Is that what you mean when you say "adequate dose" else I continue with 100 mcg.
2) What's driving this high TSH? Is it something I can contol beyond the tablet? I mean precautions, food or environmental factors. Also what else should I watch out for? Any other tests that I should get done... In your experience what other things go wrong with patients with similar history? I just want to be prepared and cautious.
1) Yes, I mean that only.
2) TSH is in indirect feedback with Free T4 and Free T3. If their levels fall, TSH levels rise, so that thyroid gland is stimulated to produce more T3 and T4. No other thing in diet or otherwise drives the TSH.
You just need to be regular with your medication, not combine with Iron, calcium etc, and test TSH once in 3-6 mths to adjust doses. Once the TSH is stable in normal range, you may check once in a year too.
Nothing else will go wrong, be assured.