Are specific forms of thyroid disease i.e. hypothyroidism and hyperthyroidism hereditary?
“I have an overactive thyroid, yet my sister has an underactive thyroid, just the opposite. Is it not strange that these two conditions have occurred in our family?” ANSWER: Both of these are termed “autoimmune” thyroid diseases: that is, they are both due to antibodies. In the case of the overactive thyroid, the antibody that has caused that condition stimulates the thyroid, and thus causes Graves’ disease. On the other hand, your sister with hypothyroidism also has antibodies but these have damaged the thyroid and caused it to be unable to function at a normal level. Although these conditions are opposite to one another, they are in fact very closely related.
