Addison's Disease
Autoimmune destruction of the adrenal cortex that removes cortisol and aldosterone together, so the clinical picture (fatigue and hypoglycaemia from cortisol loss, hyperpigmentation from unchecked ACTH, and salt-wasting hypotension from aldosterone loss) can be predicted from which hormone is missing.
First principles
Addison's disease destroys the whole adrenal cortex, not just one hormone
In the UK, autoimmune adrenalitis is the leading cause of primary adrenal insufficiency, with lymphocytic infiltration progressively destroying all three zones of the adrenal cortex. Because the cortex makes cortisol (zona fasciculata), aldosterone (zona glomerulosa) and androgens (zona reticularis), primary adrenal failure characteristically removes glucocorticoid and mineralocorticoid function together: a pattern that distinguishes it from secondary (pituitary ACTH-driven) insufficiency, where aldosterone is preserved because it is regulated mainly by the renin-angiotensin system rather than ACTH.
Educational content pending clinical review. Not medical advice.