Hypoaldosteronism is an endocrinological disorder characterized by decreased levels of the hormone aldosterone. Similarly, isolated hypoaldosteronism is the condition of having lowered aldosterone without corresponding changes in cortisol. (The two hormones are both produced by the adrenals.) Presentation
Causes
There are several causes for this condition, including adrenal insufficiency, congenital adrenal hyperplasia, and some medications such as certain diuretics, NSAIDs, and ACE inhibitors. Primary aldosterone deficiencyPrimary adrenal insufficiency
Congenital adrenal hyperplasia (21 but not 11β and 17)
Aldosterone synthase deficiencySecondary aldosterone deficiencySecondary adrenal insufficiency
Diseases of the pituitary or hypothalamusHyporeninemic hypoaldosteronism (due to decreased angiotensin 2 production as well as intra-adrenal dysfunction)Renal dysfunction-most commonly diabetic nephropathy
NSAIDs
Ciclosporin

Mechanism
Hypoaldosteronism may result in high blood potassium and is the cause of type 4 renal tubular acidosis, sometimes referred to as hyperkalemic RTA or tubular hyperkalemia. However, the acidosis, if present, is often mild. It can also cause urinary sodium wasting, leading to volume depletion and hypotension.When adrenal insufficiency develops rapidly, the amount of Na+ lost from the extracellular fluid exceeds the amount excreted in the urine, indicating that Na+ also must be entering cells. When the posterior pituitary is intact, salt loss exceeds water loss and the plasma Na+ falls. However, the plasma volume also is reduced, resulting in hypotension, circulatory insufficiency, and, eventually, fatal shock. These changes can be prevented to a degree by increasing the dietary NaCl intake.
Because it is so rare it may be sometimes confused with comedo carcinoma of the breast although the conditions appear to be completely unrelated. == References ==