Whichever reaction is chosen, the “turbo” has to be engaged and this is what cortisol allows us to do. This brings us to the famous “fight or flight” response due to cortisol, danger can be faced (fight)…or evaded by fleeing at full speed (flight)! Namely it is cortisol (and related hormones) the infamous stress hormone, which allows you to face assault and acute crises. The zona fasciculata that produces them occupies three quarters of the adrenal cortex and they play a fundamental physiologic role. Let’s start with the glucocorticoids, a name which immediately brings to mind the metabolism of sugars (glucose). Indeed, deficits in glucocorticoids and/or in androgens lead to a slowdown of metabolism (with weight gain, except in profound deficiencies when the reverse can occur), and sometimes to extreme fatigue… All this vocabulary sounds a bit dense but let us say it again: most of these adrenals hormones play a crucial role to our health. They belong to three distinct families: the mineralocorticoids secreted by the zona glomerulosa, the outermost layer of the adrenal cortex, located just under the capsule of the gland the glucocorticoids secreted by the zona fasciculata situated just underneath, representing the middle layer of the adrenal cortex and the androgens secreted by the zona reticularis, the inner most layer of the adrenal cortex, in contact with the medulla situated at the centre. It is essentially the action of the adrenocorticoids that we will review here. They envelop the adrenal medulla, which secretes adrenalin and noradrenalin, two hormones produced in response to stress, but which will not be covered in this section. We will focus here on the adrenal cortex. It must be recognized that the biochemical pathways of the adrenals do present a certain degree of complexity. It is hard to understand this ostracism, but it explains why numerous thyroid treatments fail… Many patients benefit from an evaluation of their thyroid function, but it often fails to address their adrenal function, even though the physiological role of these glands is equally important. We shall return to the thyroid gland later, as it is a very popular topic.

Hospital medicine recognizes this rule as well. Therefore treating the weakness of one of them, without proper evaluation and correction of the other, should never be considered. Let’s be clear it is of the upmost importance to establish and maintain a strict equilibrium between the adrenals and the thyroid. Furthermore they are also inseparable from thyroid function.

Having mentioned many times these infamous adrenal glands, it is time to elaborate further on their crucial endocrine function and why it is essential to our health.

Adrenal cortex hormones function