Poor adrenal function is one of the main causes of thyroid treatment failure, iron being the other one. Low cortisol is a subject in itself with it's own yahoo group and own web site so I am not going to go into the treatment of it here. I will talk about the symptoms and stress the importance of it though. You MUST ensure that the adrenals are strong enough to withstand thyroid treatment and support them if necessary BEFORE starting thyroid treatment of any sort.
Like iron it's not coincidence that many thyroid patients have adrenal issues, being low in thyroid hormone CAUSES adrenal stress and this follows a pattern, initially cortisol levels go UP as the adrenal glands add extra cortisol to make up for lack of T3 (giving high cortisol symptoms), after a period of time (sometimes years) they cease to be able to deliver this extra cortisol and "Adrenal Fatigue" sets in and low cortisol is the result.
Adrenal symptoms are many depending how bad the problem is and include:-
The hypoglycaemia causes adrenaline. If you eat sugary carbs at bedtime or even
late evening you are asking for trouble unless you have very healthy adrenal and NO
insulin problems at all. This is because the instant high sugar in a candy bar triggers a
VERY strong insulin response., If your adrenals are not just REALLY happy and healthy they
will not make enough coritls particularly at night to raise your glucose after that big
surge of insulin drops it so then you get hypoglycaemia and this causes adnrealine. around
3 AM is the body´s;s normal time to have the lowest glucose of the day. This
is due to the lowest cortils and not eating for 5 hours.
Other low cortisol symptoms are:-
One of the best ways of making use of temperature as a diagnostic tool for adrenal and thyroid issues is to take temperatures and graph them the way shown in this link. We don't agree with everything the author of that site advocates but are very impressed with his temperature graph. I've put together some more information on temperature and it's dynamics with T3 and Hydrocortisone (HC) and have put it here
There are instructions with the graph that show the interpretation of it but basically an unstable average temperature between successive days indicates low adrenals which will need supporting in order to stabilise the temperature before your body will be able to tolerate enough thyroid hormone to raise your temperature and feel well.
If your temperatures are unstable then the "4 times a day" adrenal saliva test is the best way to find out what happens during the day. This can be ordered in both the USA and the UK without a prescription or involvement from your Dr. There are lab resources on this STTM page. You can get labs done withoutt a Dr's prescription, often at considerable cost saving.
If your adrenals are low causing unstable temperatures then they need support, Isocort can help in mild cases or Hydrocortisone in more severe cases. If temperature tests indicate that you have an adrenal problem DO NOT START thyroid treatment until it is sorted. Go and have a look at the adrenals group web site, read through it, Join the adrenals group, the links section of their Yahoo group has links to labs where you can get the Saliva test done, this is the gold standard and can be done without a Dr's prescription, when you have the results of the saliva test post them on the Yahoo group and people will help you interpret them.
The Saliva test is the "Gold Standard" for adrenal function, Dr's often want to use blood tests but they are less reliable, the don't show the cortisol levels through the day, only at the time of the blood draw, and the stress caused by going to the Dr and having the blood drawn can often totally skew the blood test anyway.
Hopefully this page has stressed the importance of cortisol to thyroid treatment, it is the most common cause of failure of thyroid treatment with iron a close second to it. The combination of low iron and low cortisol makes for a very bumpy ride when trying thyroid replacement unless you sort it out FIRST.
There are more adrenal resources here
Guidance to show your Dr on Adrenal support is given here on the STTM site.
There is a lot of information out there on the web on Adrenal insufficiency and I am not going to repeat it here, this site is specifically to help with RT3 issues.