There could be several reasons for why you are feeling like crud these days, and your doctor would be the best person to sort out the issues and tell you WHICH of the possibilities is going on. But I can give you a thumb-nail sketch of what two or three of the issues are.
First of all, you could be sick with an infection. Obviously, the doctor would have looked for this. But sore throat, fever, etc. MIGHT be a sign of infection. It is not necessarily the likeliest possibility, but it is a possibility.
Second: There is a period of time, about a week or so after RAI, when we become more hyper than ever, briefly. It can definitely make you feel like the walking dead, with all of the hyper symptoms, including fatigue, at the strongest levels YOU’VE ever experienced. As the thyroid cells are damaged by the RAI, they pour their stored supplies of thyroid hormone into the body. Thyroid hormone has a “life span” in the body, measured in “half-life” terms (i.e. after a certain period of time, half of it is still there, working). T4 has a half life of 6.7 days. T3, the most potent of the thyroid hormones, has a half life of three-quarters of ONE day. So this period of heightened hyperness is self-limiting. The damaged cells are not making NEW hormone, just releasing hormone already created. Also, as the thyroid cells are damaged, it stands to reason that you will develop soreness in your throat area. HOW sore things get vary greatly from one patient to the next. In my own case there was almost no soreness whatsoever. But I know of others who had significant soreness for a while.
The third possibility I can think of is that you may be experiencing a lowering of your thyroid hormone levels in your blood, maybe even toward hypo levels.
Your doctor is the person to seek advice from here, as to what is going on, what your levels of thyroid hormone are, and whether the dose of beta blocker you are on is still appropriate. Please don’t be afraid to call and ask these questions, even if your doctor told you to “check back in in six weeks” or something. That period of time is an educated guess. And AVERAGE. How fast any of us respond to the RAI is individual. Some people respond quicker than their doctors expected, while others respond much, much slower than their doctors expected. The only way the doctor is going to know where YOU fit into the scheme of things is for you to stay in touch, asking questions about issues like the ones you raised here.
Wishing you good luck, and I hope you are feeling much better, soon.
Bobbi — NGDF Asst. Online Facilitator
Bobbi@ngdf.org