My TSH is 200, I don't have symptoms of under-active Thyroid, what else could it be?

The standard reference range for TSH for adults is between 0.4 and 5.0 mL, but values may vary among labs. Things that could have affected the results are, X-rays that used iodine dye within the last 4 to 6 weeks, pernicious anemia (low Vit. B-12), rheumatoid arthritis, Graves disease, an error at the lab. Talk to your Doctor about the results and maybe have another lab test done.