Responsible for the production of three hormones:Ĭortisol secretion is controlled by the hypothalamus-pituitary-adrenal axis.Ĭorticotropin-releasing hormone (CRH) is released by the paraventricular nucleus of the hypothalamus. The innermost aspect of the adrenal gland, composed of a single layer. However, in women where the other site of production is the ovaries, absence of adrenal androgens may lead to symptoms (see 'Clinical features' below), Adrenal medulla In men the testes produce the majority of androgens, as such deficiency of adrenal production does not tend to cause symptoms. Zona Reticularis: androgens - produces dehydroepiandrosterone (DHEA).Zona Fasciculata: glucocorticoids - release controlled by hypothalamic-pituitary-adrenal axis (described below).Zona Glomerulosa: mineralocorticoids - aldosterone is the key mineralocorticoid, release primarily controlled by the renin-angiotensin system (described below).

The adrenal cortex is the outermost aspect of the adrenal gland. The shape can distinguish laterality with the right gland a pyramidal shape whilst the left is more semilunar. The adrenal gland is divided into two functionally distinct components, an outer cortex and an inner medulla.Īlso termed the 'suprarenal' gland, the adrenal gland sits atop each kidney. On occasion, patients can present with an 'Addisonian crisis', which refers to a medical emergency caused by profound glucocorticoid and mineralocorticoid deficiency that may be triggered by intercurrent illness. This rarely affects men where the testes are the primary site of androgen production. In women features of androgen deficiency - including loss of libido and hair loss in the axilla/pubic region - may be seen.

Loss of normal glucocorticoid and mineralocorticoid function leads to dehydration, weight loss, abdominal pain, nausea & vomiting and mood disturbance.

Tertiary adrenal insufficiency: caused by a reduction in corticotropin-releasing hormone, most commonly seen following chronic glucocorticoid steroid use.

May be seen as part of panhypopituitarism, an isolated deficiency, following brain injury or secondary to medications.

Secondary adrenal insufficiency: caused by a reduction in adrenocorticotropic hormone release.

Primary adrenal insufficiency (Addison's disease): caused by destruction or dysfunction of the adrenal cortex.

The adrenal glands sit atop each kidney, they are an important endocrine organ responsible for the release of catecholamines (adrenaline, noradrenaline), glucocorticoids, mineralocorticoids and sex hormones.Īdrenal insufficiency occurs when there is a reduction of glucocorticoid +/- mineralocorticoid production such that normal physiology is interrupted: Addison’s disease (primary adrenal insufficiency) is caused by destruction or dysfunction of the adrenal cortex.