Q.Describe Addison's disease with reference to the gland affected, its cause and its principal symptoms, and explain why it can be life-threatening if left untreated.

[!TLDR]

Addison's disease is adrenal cortex hypofunction (deficient cortisol + aldosterone), causing weakness, low BP, salt craving and skin darkening; untreated, it can cause fatal circulatory collapse. …

Addison's disease is caused by destruction or hypofunction of the adrenal cortex, resulting in a deficiency of both major classes of adrenal cortex steroid hormone: glucocorticoids (chiefly cortisol) and mineralocorticoids (chiefly aldosterone). Because cortisol normally regulates carbohydrate/protein/fat metabolism and mediates the body's response to stress, its deficiency in Addison's disease produces chronic weakness, fatigue and an inability to cope adequately with physical or infectious stress. Because aldosterone normally promotes sodium and water reabsorption at the kidney, its deficiency leads to excessive loss of sodium and water in the urine, producing low blood pressure and a characteristic craving for salty food as the body attempts to compensate for ongoing sodium loss. A further characteristic symptom is patchy darkening (hyperpigmentation) of the skin, which arises because the low circulating cortisol removes the normal negative-feedback restraint on the pituitary, so ACTH secretion rises; ACTH is chemically related to melanocyte-stimulating hormone and, at the abnormally high levels seen in Addison's disease, also stimulates melanocytes, darkening the skin. …

Trace each symptom back to the specific hormone deficiency that causes it (cortisol deficiency -> weakness/poor stress response; aldosterone deficiency -> low BP/salt craving; secondary ACTH rise -> skin darkening), then explain the life …

Describing Addison's disease symptoms without linking them back to which specific missing hormone (cortisol vs aldosterone) causes which specific symptom -- the skin-darkening symptom in particular is often left unexplained, when it …