Thank you.
Generally as patients we have sluggish cortisol release, so we have sufficient adrenal reserve, it's just that our brains don't release it quickly enough when the dynamic world requests it.(If we look at general 'CFS' and the research results of synacthen tests the adrenals show a 'blunted' response to stimulation, but a sufficient rise in cortisol not to be Addison's disease).
If that was true, for some, you could theorise that the immune system somehow affects the brain, increases cortisol (temporarily) and makes us feel unusually good, as we aren't so drained?
This may be hogwash, but I am noticing with myself clinically low levels of cortisol at rest, but normal levels with stressed in repeat cortisol tests at home. In the hospital, as I am stressed, the resting cortisol is 'normal'. This would imply the brain is dysfunctional in releasing cortisol and only works when 'prodded', otherwise it's too low. Ergo you can argue ME CFS is a dysfunction of brain cortisol, not adrenal glands. The problem here, as I also found out, is that you need the correct test - a pituitary gland test in which the brain is 'stressed' with a hormone - such as Glucagon.
As predicted when this was done in myself, I didn't produce enough cortisol, thus the low brain cortisol idea, at least in myself, is correct.
I only realised this recently, that the levels of cortisol in ME CFS research, aren't done at home. So if patients report they can't cope with stress, what's going to happen when blood is drawn (levels will go up anyway due to pain/expectation - false readings on tests) in a hospital setting too - more false readings? The levels will be higher than at home. Now naturally, doctors don't realise that ME CFS patients are totally stress intolerant, draw blood in the doctors office (meant to be done at 9am), and it's low normal or normal so they 'miss' our levels done when we are totally calm and chilled out - home phlebotomy.
So perhaps, in some people, an infection can create this phenomena too (increase cortisol - as in travelling to a hospital blood draw), and you feel unusually good for a short time, but then crash afterwards, when the trigger is switched back off again (possibly hit by delayed PEM as you did more, as you could do more for a limited time, as your cortisol was raised.
Have any of you also noticed, sometimes you tend to be able to do more physically when in the hospital, under pressure? Maybe this is adrenaline giving you 'power' that you don't have at home, but I did wonder if it's actually your body operating with the correct level of cortisol, for a short while and you can feel it.
Thus if 'stress' can do this, perhaps infection to (for some) as we know that infection raises cortisol (hence infection can kill Addison's patients, as they have no cortisol left to cope with the stress on the body of an infection).
Who knows. I expect this is silly, but it's fun thinking about it.