Hyperthyroidism How Is It Possible To Have Both Hypothyroidism And Hyperthyroidism?

How is it possible to have both hypothyroidism and hyperthyroidism? - hyperthyroidism

I'm 14 and I learned recently that Oprah Winfrey has both hypo-and hyperthyroidism. I learned that many others have two. I know a lot about the endocrine system, so I know that hyperthyroidism caused by HRT is hormone bodybuilding, and hiccups caused by HRT does not, then how is it possible to have both at the same time?