What do i do if my tsh levels are normal, but my free t4 is low, and i am having hypothyroid symptoms?

Central hypothyroid: Free T4 assays can sometimes be unreliable and you and your physician will be better off if you have your total T4 measured instead along with T3 (liothyronine) update to calculate what we call free thyroid index. If you have symptoms of hypothyroidism and your T4 remain level despite normal TSH then you may have a type of hypothyroidism called central hypothyroidism (your pituitary hormones should be checked).

Check RT3: I suspect you may be functionally hypothyroid. Check free T3 and reverse t3. Ft3 should be in upper range and rt3 in lower range. If your ratio is off, you may need Armour Thyroid or t3, and synthroid (thyroxine) would be the wrong med for you.

Undiagnosed hypoT?: Hypothyroidism can be primary - caused by a weak thyroid gland or secondary to other hormonal problems, like a pituitary problem. Or your thyroid can become dysfunctional secondary to high insulin, estrogen or cortisol. If you have functional hypothyroidism, this problem can go undetected by routine screening tests. More extensive testing can often reveal abonormalities. This is very common.