Yes, carpal tunnel is common with hypothyroidism and it could cause issues with your thumb. If your dose of levothyroxine is optimal, your symptoms should be alleviated.
You should always get copies of your labs whenever you have blood work done, and keep them for your records. I write on each of mine, what med/dosage I was on at the time of the blood draw and what, if any symptoms I was having. My labs have become a running record of my health conditions and I can change doctors without having to have records sent from one doctor to another because I have them.
I don't have any blood work. I think I have carpal tunnel syndrome, is that a common thyroid thing and would that cause the symptoms I mentioned? Thanks for your reply :)
If you were on a dosage of levothyroxine and all your symptoms went away, then they came back, it's probably safe to say that your symptoms are thyroid related and have nothing to do with ALS.
Do you have copies of your most current thyroid related blood work? If so, please post the results and be sure to include reference ranges, which vary from lab to lab and have to come from your own report.
Do you know if you have Hashimoto's Thyroiditis? If so, your levo dosage will have to be adjusted periodically to keep up antibody destruction of your thyroid.
Have you talked to your doctor about the problem with your thumb? While that's not, typically, a thyroid symptom, neither do I think you have ALS, so you might have your doctor look into it, if the symptom is problematic.