So when you go in for your annual check-up, you should request testing for thyroid function. Specifically ask for free
T3, free T4 and TSH. Note that free
T3 and free T4 are not the same as total
T3 and total T4. the tests for totals are somewhat obsolete and not very useful compared to the Frees. If the doctor resists testing for FT3 and FT4, then you should insist on it and don't take no for an answer. Remember that you are the customer.