so far as my knowledge goes, thyroid problem is not covered under disability. But, more important than that, u need to be aware of the fact that hypothyoridism is commonly associated with depression or anxiety (symptoms may be decreased apetite, sleep problem, worry, palpitation, loss of interest in work, and finally, feel like disabled, leaving job etc). And this can very well be treated by medications, by a psychiatrist. To add, treatment of hypothyoridism is complete if we treat associated depression or anxiety, if any, and vice-versa.