Just been to the docs for a regular meds review. Mentioned i have been feeling exhausted and getting migraines etc. She told me my "thyroid levels are all over the place" and my tsh is 15. I am so shocked, its never been this high. Why would it change so significantly. I take my meds religiously and it was fine last blood tests a year ago. I dont understand what happens. I have been diagnosed with an underactive thyroid for 15 years, this is the first time i have got scared.