A small thread on stress and immunity. And how the former causes more damage than we care to acknowledge. Let us start with the simplest axis - the Hypothalamic Pituitary Adrenal axis. Will try and keep things simple.

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So, there is a stressor. Physical or psychosocial. A few things happen straight away – the hypothalamus releases Corticoid Release Hormone [CRH] into the Pituitary, the Sympathetic Nervous system [autonomic – SNS] fires up, Parasympathetic NS [autonomic - PNS] down-regulates

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..the Pituitary releases ACTH into the adrenal gland which in turn starts flooding the circulatory system with glucocorticoids. Biology 101 that most of us know.

At this juncture, let us remember that neurotransmitters are fast acting, mediating and switch off when the stimulant dampens down. Unless of course, thought/rumination keeps the circuit lit up like a Christmas Tree.

Hormones [Cortisol] on the other hand, release a bit later, act slowly [comparitively], spread all over & act on multiple cells in multiple regions of the body [remember, no cell in the body is more than a few cells away fm a blood vessel/capillary] & take much longer to fade out

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Typically, CRH action will get triggered within a second, will last a few seconds or minute and when the stressor goes, it will take a few seconds or a minute to die out. Threat is over, lion [real or metaphorical] has gone, job done!

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Hormones on the other hand, will start flooding the blood a minute or two later, will spread all over, act in multiple areas and will typically take a couple of hours to be cleaned up after the CRH release halts.