Read an interesting article today, thought I'd post basics. Link at the bottom for whole article.
*Must get results from Saliva testing not blood.
High cortisol can block the conversion of T4 to T3, favoring conversion to RT3 and putting you further into a hypothyroid state.
Both high cortisol and low cortisol can cause problems raising NDT, first causing hyper-like symptoms from excess adrenaline, then causing too much RT3.
Treatment for high or seesawing cortisol are adaptogens like
Ashwagandha, Rhodiola, Relora, Eleuthero, Maca, Schisandra, etc. You can combine them, or take alone.
When three or more saliva tests show low people find success in using over-the-counter Adrenal Cortex (ACE). If three or more are seriously low in the ranges, they turn to prescription HC aka hydrocortisone.
If you are making too much cortisol then ACE shouldn't be used.