My doctor has scheduled me for a Thyroid scan with Uptake. My TSH is high, but my T4 & T3 are in range. I have a small goiter. Does this mean hypo or hyperthyroidism? If they use a radioactive iodine, what does this do to the thyroid? What if I am allergic to shellfish? Can I still have this test? I feel as if I have adrenal fatigue But he Hasn't checked for that yet. Should that be checked first to see if it's throwing my thyroid off? I'm not on medication yet. Will the radioactive iodine kill my thyroid and make it so I have to have medicine from now on? The reason I ask is I know someone who had taken something like that they said would stop the thyroid and they ended up taking medicine for the rest of their life.