Adrenal glands not producing enough steroid hormones (cortisol and aldosterone)

Primary adrenal insufficiency:

Addisons disease - In this condition, there is destruction of the entire adrenal cortex. Glucocorticoid, mineralocorticoid and sex steroid production are therefore all reduced. This is also called Primary Adrenal Insufficiency.

• The most common cause is autoimmune.
• Worldwide the most common cause is TB
• Other causes:
  • Surgical removal
  • Trauma
  • Haemorrhage (Waterhouse-Friderichsen syndrome)
  • Infarction
  • Less common: neoplasm, metastasis (e.g. bronchial carcinoma), HIV, APS, sarcoidosis, amyloidosis

Secondary adrenal insufficiency:

• Inadeuqate ACTH stimulating adrenal glands as a result of loss or damage to pituitary gland = low cortisol release. Can be due to:

• Surgery to remove pituitary tumour

• Infection

• Loss of blood flow

• radiotherapy

There is also a condition called Sheehan’s syndrome where massive blood loss during childbirth leads to pituitary gland necrosis.

Tertiary Adrenal Insufficiency

the result of inadequate CRH release by the hypothalamus. This is usually the result of patients being on long term oral steroids (for more than 3 weeks) causing suppression of the hypothalamus. When the exogenous steroids are suddenly withdrawn the hypothalamus does not “wake up” fast enough and endogenous steroids are not adequately produced. Therefore long term steroids should be tapered slowly to allow time for the adrenal axis to regain normal function.

PC