"Because some folks have antibodies for both Hashimoto’s thyroiditis and Graves, they potentially can fluctuate between the two states depending upon which antibodies predominate." This is what I meant by both hypo- and hyper- at the same time. Obviously, "same time" was a poor choice of words. After doing some reading, I guess it doesn’t really matter if a person is both becasue the doctors want to treat it the same—kill the tyhroid, make it hypo.
Thanks for your reply.