Just had a letter from endo saying he is arranging a synacthen test. I've googled it so think I know what is involved, but not awfully sure of the reason for it.
Be grateful for help to understand the purpose of this test, and if it helps with diagnosis of anything? Also from anyone with experience of it. Thanks. j
A Synacthen test is done when it is suspected that cortisol levels are lower than they should be, or you are experiencing debilitating symptoms such as weight loss, fatigue, needing a lot of sleep etc. They are testing to see if you have adrenal insufficiency, either primary (Addisons) or secondary. Primary (Addisons) is where the adrenal glands are compromised & not working. Secondary is where the issue is with the pituitary not producing enough ACTH (hormone) to stimulate the adrenal glands to produce cortisol. To see if it is the pituitary they need to do an ACTH blood test at the start of the test as well as a baseline cortisol level. The ACTH needs to go straight onto ice. You are then injected with artificial ACTH to see if it stimulates your adrenal glands. The base level should be at an optimal level of around 500nmol/Ls at 9m & then should increase by more than 200nmol/Ls at 30 mins, some will also test at 60mins as well. Not all Endo's are good at interpreting SST so it's important to have one that is knowledgeable. If you are on Facebook then join the UK Addisons info & support group where there are many clever folks ! I have secondary adrenal insufficiency. Hope that helps a bit?
Thanks for all that valuable information PaulineS. I'm not on Facebook but I'll google Addisons for interest. From what you say the endo probably suggests this due to my weight loss (and fatigue
). Another test to narrow down the causes it seems, which in many ways is a relief to me - perhaps I'll get to the bottom of this eventually 
Synacthen Test Result 
Is a Short Synacthen Test enough?
Reacted during synacthen test.
Short Synacthen Test - Update
