Why does Endo say ACTH test is not relevant wou... - Thyroid UK

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Why does Endo say ACTH test is not relevant wouldn't a low result indicate secondary Addisons?


I recently had a SST due to low cortisol. The endo said my results were good and discharged me without discussing them with me. I wrote to him to ask for ACTH blood test because they didnt test this when i had my SST but he has refused. See attached letter. I really don’t understand this response particularly as he says even if ACTH is low they don't treat - surely a low result would indicate secondary Addisons?

6 Replies

Previous post from 5 months ago showed you were under medicated and low Ft3


Did you get levothyroxine dose increase or T3 prescribed to improve low Ft3

Low cortisol often improves as T3 rises

Thanks for your reply. My memory is terrible at the moment some days its difficult to function. I looked at my previous post, i did try a small amount of T3 but i just cant tolerate even a tiny amount as i go hyper and very jittery. My latest results from medichecks are

TSH 0.68 (0.27 - 4.2)

T4 19.6 (12 -22)

T3 4.99 (3.1-6.8)

Taking 75/100mg of levo

I take vitamin D B12 and magnesium

My atrial fibrillation has increased in frequency so i am taking betablocker which i know interferes with levo but no medic agrees with me!

I do believe my symptoms are endocrine but it’s difficult to know what to do.

I'm afraid you have your terminology slightly muddled up - there is a condition known as secondary adrenal insufficiency, but no such condition as secondary Addison's Disease.

If you look at "Types" on this page it explains the terminology :


and the effects of each type i.e. what is low and what is high is described in this section :


You may have heard of adrenal fatigue, but this is not the same as adrenal insufficiency. Doctors don't "believe in" adrenal fatigue, they only "believe in" adrenal insufficiency.

Adrenal fatigue, as far as I am concerned, occurs when someone has cortisol issues which can be fixed i.e. no part of the adrenal/cortisol system has completely "failed", it is just not working very well and it can be brought back to life with the right levels of thyroid hormones, a good diet, and optimising nutrients.

Your endo is wrong about ACTH not being relevant, and it should have been measured during an SST. You might find this document of interest - the endocrine bible - read pages 68 - 70 for info on the SST.


It contains information on how to prepare for testing, how to carry out testing, and how to interpret the results for any tests usually performed in an endocrinology department.

PaulineS is knowledgeable on cortisol issues and may have some useful information for you.

Thank you for your response and the information. I am afraid that endo is adamant that i have been discharged so i wont get any further testing carried out so I am on my own now. I just cannot understand his response to ACTH. He has also told me that my renin is out of range and my aldosterone is bottom of the range but no action because i don't have conn’s , i don’t understand this either

I am considering some further private testing but don’t know where to go from here.

Sadly many Endo's are not conversant with pituitary/adrenal issues & this sounds as though this may be the case with you. Ideally an ACTH test should be done at the start of the SST to see if it is a pituitary issue. In the SST you are injected with artificial ACTH so if you responded well to it then the issues isn't with your adrenal glands but may be due to a pituitary issue. Has he given you the results of the SST? Ask his secretary to send them to you, or your GP may have them. If you are unable to get them this way then contact medical records at the hospital & ask for copies of your notes plus the tests done. It is your right to ask for a second opinion, you can ask your GP to refer you to your nearest Centre of Excellence. if you message me where i the country you are I can tel you which your nearest one is.

Thanks for your advice. Yes i did get the results which were:- Baseline cortisol: 283

30 mins: 586

60 mins: 683

Comments: any value over 420 excludes adrenal insufficiency

I also had a renin / aldosterone test on NHS as private test showed low aldosterone.

Renin low 0.2 (0.5-3.5) so below range

Aldosterone low 120 (90-700)

Ratio 600 (<680 excludes Conn’s syndrome)

I don't understand these results but I was told as low in range they don't treat which makes no sense to me. The consultant said the same for ACTH in his letter so even if low he would not treat!

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