After going to a regular general practitioner for hypothyroid (elevated TSH 4) for a year, I asked him to give me a referral to an endocrinologist. Even though levothyroxine had lowered my TSH values to very good "low normal" range, I still felt sluggish and unable to run well.
Yesterday, I met with the endocrinologist who did an ultrasound on my neck. I had one performed last year which found nothing. This time around, the endocrinologist said, "your thyroid is clearly under attack, you have Hashimoto's disease". He switched me from generic levothyroxine to Synthroid at the same dosage of .75 mg.
My question is, does this mean with Hashimotos my distance ability is now pretty well compromised and future marathon running is probably out of the question?
I won't complain about it if it is, I have had a good number of them under my belt now. Just need to think ahead on alternatives.