Fludrocortisone acetate is a synthetic corticosteroid with moderate glucocorticoid potency and much greater mineralocorticoid potency. It is used primarily to replace the missing hormone Aldosterone in various forms of adrenal insufficiency such as Addison's disease and the classic salt wasting (21-hydroxylase deficiency) form of congenital adrenal hyperplasia. It is occasionally used to treat orthostatic hypotension as well.