Anxiety and stress causes poor adrenal function, whether it is physical, emotional, psychological, environmental or illness. Re your previous post, there are many studies showing the effect that your stress hormones have on thyroid hormones after major surgery (Arunabh, Sarda, & Karmarkar, 1992).
Stress impacts both the adrenal and thyroid hormone pathway (and so the biochemical pathway that produces T3 active hormone). Once hormones are unbalanced it causes a knock on effect as all hormones are dependant on adequate levels of others.
Your Hypothalamic-Pituitary-Adrenal Axis (HPA axis) is the system that helps you respond to stress. The hypothalamus (brain) is where stress is interpreted as such but also where the mechanism to stimulate your thyroid begins.
Stimulation of the pituitary (by the hypothalamus and through separate hormone signals,) will signal the adrenal glands to release the stress-buffering hormone cortisol, and the thyroid to release T4//T3 but low thyroid hormones (caused by meds not working or being kept under medicated) can affect cortisol levels as the adrenal glands start trying to compensate.
Many members complain of breathlessness, the weird internal tremors and peripheral neuropathy. My own experiences have put this down to adrenal and cortisol issues. Waking at night are classic symptoms of cortisol issues.
A TSH of 18.0 is much too high to feel well when medicating 175mcg of Levothyroxine and would indicate your meds aren't working for you. Sometimes adding more is not the answer as there are many reasons for them not working.
Ask your GP to test Vit B12, folate, ferritin, Vit D & "9am cortisol" and post results complete with ranges (numbers in brackets) for members to comment. It would be useful to have T4 & T3 thyroid hormones tested to get a clearer picture of your thyroid function. If your doctor is uncooperative, you can use private labs as many members are forced to.
Cortisol and Thyroid Hormones.
Private labs testing
Saliva Stress Test (test ref END01)
Four saliva tests that measure the available "active" cortisol (& DHEA) secreted at set times over a 24 hours period. The results will allow you to see any imbalances in the daily circadian pattern so enabling use of correcting supplements to aid your adrenal health. Unfortunately this test is not generally used or recognised by GP's.
The cost is £77.00 which is a discounted price for THyroidUK when code A42AQ is used.