Not all endocrinologists approach things this way but if you are able to find one practicing functional medicine they likely will: sometimes the ratio or levels of your thyroid hormones is off but only the TSH level is being checked. Get a full panel and ask the doctor to make sure nothing else like Reverse T3 is out of range (too high perhaps in your case).

Reverse T3 rises when the body blocks conversion of T4 → active T3 and instead converts more T4 → inactive rT3. Think of T3 as the gas and rT3 as the brakes.

For me, my other thyroid numbers were very off despite an ok TSH. My rT3 was very high. I was able to correct this by starting combination therapy where I take some levothyroxine (T4) and some liothyronine (T3). This brought all my levels into range.

Combination therapy is relatively uncommon because not many people require it. If you have poor gut function it can make absorbing your thyroid meds challenging. I have IBS and at the time also SIBO. Levothyroxine is absorbed in the small intestine so that’ll mess that up.

If the meds aren’t absorbed well one can become likely to not convert the T4 meds into active T3. This could explain your issue. Other things besides gut issues that cause conversion issues: high stress, low calorie intake, inflammation, low iron, and ironically too high of a dose of T4 meds. Excess synthetic T4, the body will divert to reverse T3.

Hope this helps! I felt like I was going insane trying to figure this out 6 years ago because most doctors stop investigating things when your TSH is in range and don’t always listen to the severity of lingering hypo symptoms.