A symptom of an underactive thyroid is raised cholesterol and eventually heart disease if not treated along with weight gain, lethargy, brain fog, aching muscles...not enough T3 makes your blood pressure rise. Thousands of us in the same boat and needing T3.
Comprehensive bloods including TSH,FT4, FT3,B12, vitD, thyroid antibodies, reverse t3, iron, ferritin etc need to be taken to rule out thyroid issues. Post your results on the thyroid group on this site as most GP's tell you you're in the correct range when you are not!
I am one of those. Just started natural dedicated thyroid which has T3 in it(not available on the NHS disgustingly!)
Planning a march to Downing Street later in the year to protest.
I guarantee some of you will be in the same boat.